hi, I hope that this question belong here...
and the question is: what I need to have to use loops and samples on live performances? I have a band 2 guitars, bass, drumms and two vocals (hiphop and grunge oriented one) and we sound like: http://www.youtube.com/watch?v=Dn-uVO66i2E
and we want to add some loops...and we want to do it with laptop so...if any one have experience...

Probably the best place to go would be the Keyboard Corner. I don't like using laptops live, so I don't really have experience with it. Different people prefer different software, and it will depend on whether you use a PC or a Mac. I've heard people rave about Ableton Live.

You'll also need a decent audio interface. But check out the Keyboard corner - there are lots of guys over there who are doing this sort of thing and can make recommendations. You may get a bit of ribbing for esentially replacing a keyboard player with a laptop - but they'll give you good answers.