my isp has a limit of 10GB up and down per day. If I go over this limit I'am cut of for two days then 4, 16 and so on. So I wonder if there are any apps that can trottell other applications (ktorrent) access to the net at an user defined value. or shut it down.

thanks.

Are you meaning 'throttle'? There do appear to be some utilities that can help you do that, but they'll be overarching - limiting the bandwidth that your network card passes, rather than the bandwidth that any given application uses. Google for 'linux traffic shaping', or read this howto for more information. It won't be simple (you'll have to play around with iproute2 and other assorted networking utilities), but it can definitely be done.
If you're mostly concerned about limiting bittorrent usage, I'd suggest turning your client completely off when you're not actively downloading something, limiting the upload speed, and other measures of that type.

Found an app GKrellM it lets me se how mutch I haw uploaded and downloaded in a day, in a nifty window, and its also possible to make plugins for it, so I think I'm going to try (when I have time) to make one. in the meantime I just have to check up on my downloading and kill ktorrent manually.

but thanks any way

PS: that windows accelerator seams expensive.

That sounds like an infinitely better way to do things, I agree...trying to implement that traffic shaping sounded like a really tough way to achieve your goal =/

And yeah, it would be pretty expensive...we had a thread awhile back that turned into a discussion of whether it would be better to assume that you're only throwing the Windows CD's out of the window...less damage when they hit the ground, but cheaper