How to get rid of 'other' space

I tried to use iSpirit to add mobileterminal since the version in cydia doesn't support ios 4, and half of my apps magically disappeared..

After numerous reboots, I opened up itunes to see that i have "0 mb" allocated towards apps, and 5gb allocated for "other" (which is how much my apps are!!)...

I googled and it turns out the only way to clear this "other" space is to Restore, but the problem is, I don't have any backups, which means that i would lose my jailbreak + cydia + all tweaks, etc...

Is there any way I can use winscp or something and clear this "other" space?

btw, how much 'other' space is normal if you have 4 gigs of music and 5 gigs of apps?