Here are a few weekend projects that may be fun diversions for E61 owners:
y!p! - J2ME Yahoo Image Search client
Search, view, and save images
w!k! - J2ME Wikipedia Client
Search and view Wikipedia articles
Mobox - J2ME box.net client
If you have a box.net account you can manage your data through this client.
The source code is posted and the applications were tested using an N70 and E61. The apps should fine work on other S60 devices.