I recently used a beta program called Twikini. Twikini is a wonderful Twitter client for Windows Mobile.
I installed it after not being satisfied with TinyTwitter. What got me started on Twikini was the ability to filter out my replies. What kept me was the speed and ease of use.
With builtin location updates from GPS, the ability to tweet pictures, short url integration, and Windows Media integration it is a feature rich app.
It also comes with various themes. Here are a couple of sample screen shots…
At $4.95 it is definately a steal, and they even have some creative payment methods!
So if you are a Windows Mobile user and need a great Twitter client, then take my advice and install the first and last one you will ever need!