Here are some tips from my experience on mobile web design.

Couple of years back you needed to learn WML (Wireless Markup Language ) to design a web site for mobile phones but that is not the case anymore. Mobile web design is not different than normal web design! If you have simple html, JavaScript and a server-side language skills you can design a mobile web site. DO NOT PAY companies to convert your web site to mobile web site.

Having said that you need to keep in mind couple of points below.

Design must be simple:  Mobile phones have small screens and memory. You need to make sure you are not overloading web site with information. Make it simple as possible. Do not use too much JavaScript.

Design touch screens on mind:  Most of the modern phones have touch screens and navigating around a site with fingers is quite hard. Do not make your visitors suffer. Try to design link tittle as large as possible without ruining overall structure of your site.

Test your web site: Try your web site on as many phones as possible. Although it would be ok to design for most common screen dimensions of today (240*320) as phones get advanced their resolution and screen sizes increases. Try not to set font size too small. You can use different css for different phones to achieve better results.

Obey web standards: Current standard for mobile web design is XHTML Mobile. You caa read more about it at http://en.wikipedia.org/wiki/XHTML_Mobile_Profile. Set your mime type correctly to application/vnd.wap.xhtml+xml. But keep in mind that if you want your mobile web site accessible via PC you should set server mime type to txt/html then set mime type on page with head tag <meta http-equiv="content-type" content="application/vnd.wap.xhtml+xml; charset=utf-8" />

You do not need special hosting for a mobile site! Just use your current hosting.

You do not need a .mobi domain name for your mobile site. 

If you are using Asp.Net, do not use Asp.Net controls, post backs etc: Asp.net's VIEWSTATE feature clutters your page and keeps load times high.

Try to use Url Reverting to make page names short and clear

A rough advert slipped in to Admob's publisher network costed money to quite few people who use iPhone application called Talking Tom Cat.

Application designed for kids was using Admob adverts to support free version and some adverts was designed to trick users/children to click and dial premium rate numbers.

Admob said: "Click-to-call ads with premium numbers are classified as age-appropriate and normally would not appear in apps for children. We will work with the app developer to block these ads if we discover they are showing."

From TheRegister;

Developing apps for Android, iPhone and iPad ? Go to http://inmobi.com/smart-dev/worlddevfund/ to grap some of $2 Million from InMobi.

Inmobi offers 100% revenue share for  Android, iPhone and iPad untill $2 million depleted. You will be paid 100% of you advertising income! Hurry up, first come first serve!

Personally as a mobile web developer I am a bit disappointed. Mobile web developers left out of this fund. I understand InMobi's aim to grab some share from juicy App Market(s) but there are thousands of mobile web developers who would start to use InMobi with such campaing!

public static string GetUa(HttpRequest hr)
    {
        try
        {
            string visitorBrowser = hr.UserAgent.ToString();
            string originalBrowser = hr.ServerVariables["X-OperaMini-Phone-UA"];
            string anotherOriginalBrowser = hr.ServerVariables["X-Device-User-Agent"]; //novarra
            
            if (!String.IsNullOrEmpty(originalBrowser))
            {
                return "OPERAMINI " + originalBrowser;
            }
            else
            {
                if (!String.IsNullOrEmpty(anotherOriginalBrowser))
                {
                    return "NOVARRA " + anotherOriginalBrowser;
                }
                else
                {
                    return visitorBrowser;
                }
            }
        }
        catch
        {
            return "No UA Found";
        }
    }

There are quite few mobile ad companies around, here is the list of main ones.

Admob  is the first and the biggest mobile advertising company. Fill rate is good and has worldwide advert portfolio. Publisher support is slow and communication is very cold and in automated manner. Pays in time. Doe not accept any adult content, even keywords like hot babes are banned.

Mojiva is slowly gaining pace. Fill rate is not too bad. Support is slow and usually feels like you are not being valued as publisher. Although you eventually get your payment, their payment system is a mess. Does accept mild adult content.

Buzzcity mainly targets Asia-Pacific region. Fill rate is not too bad. Support is ok and you feel like being valued as publisher. They recently started to expand to Europe.  Payments always on time. Publisher control panel is not fancy as others and they only provide PHP and HTML Banenr ad codes. If you are using any other technology you have to write your own by reading their API docs. Accepts adult content.

Decktrade mainly targets Americas. Fill rate is quite low. Support is good. Payments are on time. does not accept adult content.

InMobi  is one of the newest on the market and used to known as mKhoj. Mainly targets Asia-Pacific region, recently started to expand in to Europe. Support is excellent. Payments always on time and publishers valued. Accepts adult content.

AdModa Fill rate is quite low. Support is good. Payments are on time. Does not accept adult content.

AdultModa Fill rate is ok. Support is good. Payments are on time. Accepts ONLY adult content. It is the only mobile pure adult advertise company i know.

Smaato is mobile ad optimization platform were they do not signup advertisers but uses other ad platforms such as Admob to display adverts on your site and pay you VERY small share (30% at the time of writing this post). Support is bad. You never get reply to any of your questions unless you are a very big publisher with huge hits! Never pays on time. Update 21/07/2010 Please see comment below from Smaato regarding my info about Smaato

SGM is a mobile adult affiliate network where you send traffic to their adult content with your affiliate id and get paid if people visiting them from your site buys content. Mainly uses Bango to charge for content. Pays on time but don't expect too much. Support is good.

Gogole Adsense Mobile has mobile advertising platform too. They recently bought Admob and it is not yet clear if they are going to merge Admob in to Adsense Mobile or vice versa.

Greystripe is not a classic mobile ad company. Like SGM they provide you with a content site where your visitors can download free ad supported games and you earn money as your visitors click in game adverts. IT is hard to generate income and as a affiliate you don't get too much return from clicks. Support is slow.

AdFonic is one of the smallest mobile ad companies. Fill rate is low. Support is slow. I was unable to find anyone got stayed with them more than a month to gather info about payments. That doesn't mean thy are bad, I simply haven't got any information.

ZestADZ is another small mobile ad company. Fill rate is low. Support is slow. Again I was unable to find anyone got stayed with them more than a month to gather info about payments. That doesn't mean thy are bad, I simply haven't got any information.

Disclaimer. Information above does not reflect my own experience but simply collection of experiences form mobile site developers i know and forums I've read over the last couple of months. I have no reference links and your experience could be totally opposite to what it's been said about these companies in this post.