PockeTwit is a twitter client for Windows Mobile.
The main list implements "kinetic scrolling". You can drag your finger across the screen and the page follows along, as if you were pushing the content around
Skyfire Mobile Browser is a free, downloadable mobile browser that gives you a Web browsing experience exactly like PC browsing.
For the first time ever, on your phone, you can watch any video, connect with friends, listen to music, shop, and browse the web using the full-featured PC versions of your favorite websites
Nimbuzz - Enjoy free calls, free IM and all your social network friends in one place: Nimbuzz, MSN, Facebook, AIM, Google, Yahoo!, MySpace and more.
See who's online 24/7, send pics, music, voice messages and videos for free
Aloaha SecureSMS - Much has been said about email security but hardly anything about SMS security. Considering the amount of sensitive SMS sent on a daily base that is pretty surprising. As the recent stories with manipulated Nokia 1100 (just Google it) have shown it is very possible to intercept SMS from other users
TeaShark gives you full web browsing on your mobile phone with superb usability and performance. It renders web pages the same way as desktop browsers. No more 'mobile web', your favourite sites are the same on your phone and the desktop
Slick is messenger application for mobile phones. It allows you to chat with your friends connected though various online messaging applications.
Currently it is still in development, and alpha version is available for free for public testing
SPYPhone GOLD Internet Edition is software that you install on a mobile phone. After installation, SPYPhone secretly records events that happen on the phone and delivers this information to a web account, where you can view these reports 24×7 from any Internet enabled computer or mobile phone
AvantSlash allows you to read Slashdot on a Windows Mobile, Blackberry, Smartphone or Palm based device (either online using a web-browser or offline using an application such as AvantGo) or from an older WAP enabled mobile phone