A new release of iBackApp is available for download and now with iOS 5 support.
Previous backups from iOS 4 should work just fine. Stay in the comments.

iBackApp is a tool that will backup all the important stuff from your iPhone quickly: Contacts, Bookmarks, SMS and more.

You will need:

  • A jailbroken iPhone with iOS 4 or 5.
  • Windows with .NET framework 2.0 (You probably have it already)
  • Itunes 10.x

[UPDATE]
Version 1.3.1 will now allow you to extract your files from the .ibackapp file. Some users reported that some of the stuff does not backed up. I recommend a reboot right after the restore.
Right click on the restore entry will popup a menu to extract the files.
Here is the download link.