Found the following site, could be useful to soem of you.
http://www.gamejump.com
Basically the application downloads a small advert each time at startup. You shoudl be aware of what you are charged for data and make an informed choice if this is acceptable to you.
In teh UK you need to download to teh PC and bluetooth/cable/IRDA it to your phone, direct download only available in USA
For those whose phones have bluetooth but PCs don't a USB b/t adaptor is ~£5-10