Another option to remove large "Other" files
After I upgraded my first gen. iPad to iOS5, I had an "Other" file that was 12.8 GB's. I am not certain how large it was just beforehand, but I am pretty certain it was not that large.
Here is what I did to correct it.
I connected my iPad to my MBP and fired up iTunes. I unchecked the sync options for all media - including music, videos, books, Podcasts, etc. I unchecked everything except for Apps and everything on the emails, calendars, etc. tab.
Then I sync'd my iPad. The "other" file(s) went down to 0.63 GB.
I then re-checked everything that I had previously unchecked and ran a sync. It took a while, but everything re-sync'd and the "other" remained at 0.63 GB's.
FWIW, I didn't want to do a restore as my last restore point was just before upgrading to 5.0. Anyway, the above steps worked for me.