I just finished up coding new features for Twim v1.12. New features in this release:
- yfrog support
- Favorites support
- File based photo upload
- Recent timeline not loaded on startup automatically (to reduce bandwidth usage)

yfrog.com
With the latest release you can share your photos with yfrog service in addition to existing TwitPic and Twitgoo services. Now you can also send image files so your phone doesn’t have to support Media API. The file based photo upload displays a file browser so that you can select a file to be uploaded to a selected service.
Another big feature is the favorites support. You can now mark statuses as favorite. Favorite statuses are displayed in separate timeline. I’ve been using this feature to store statuses containing interesting links so that I can check them from desktop browser later on (http://twitter.com/favorites).
Twim is still free and you can download the latest binaries from here.
People have mentioned many good ideas for the future versions of Twim, like auto-refresh for recent timeline and incremental update to reduce the bandwidth usage.