I kept getting a low on space warning so I decided to go into the 'Managing Applications' menu and found some apps had a large 'Data' reading. The Twitter app in particular was using just under 10mb. I decided to click the 'Clear Data' button and it warned me that this would clear all my account settings etc but I thought I'd give it a try. Anyway, it brought the data level right down to virtually nothing and my Twitter app didn't lose any of my account settings. I didn't even need to sign in again and everything works like it did before and I now have some free space. I did the same with the Facebook app. The data has come right down, I was required to sign in again with this though. I had about 13mb of space left before, now I have 45mb. So... is this something we need to do periodically in order to free up space? Do certain apps just continue to build up data until we clear them out?