clockworkmod/backup can it be removed? Today I installed cyanogenmod JB on my galaxy note and I found this huge directory (2.47GB) in the /sdcard partition. Can it be removed or it could be useful? Can I move it on my pc?

Thanks in advance
Two times yes: Of course it can be removed, and of course it can be useful. At that place ClockworkMod stores the nandroid backups you've created with it, and from that place you can restore them when need for that arrives.

In case of an external SDCard, and when space on it is precious to you, you could simply copy its contents to your computer, and then empty the directory. Or just keep the latest backup on it. If you need to restore one of the removed backups, it then would be possible to use a card reader, copy them back, and re-insert the card to your device so they can be found.