i got a guitarport secondhand last week and its quite cool. all the amp modelling/effects etc are a pretty good way to get loads of different sounds to play about with. you can rip tracks from cds, or download stuff online, to jam along with and record stuff.

i had a few probs with setting it up on my laptop, it says you need 400ish mhz prossessor, and i have a 900mhz prossessor in my laptop but it still gave probs. i tried it on my desktop pc, which is about 3000mhz prossessor and it was ok. i got a mate to tidy up my laptop and it now works nearly perfect, so be aware that if your pc is running other applications then the guitarport program starts to crackle and pop!!

its no substitute for my marshall amp, but its a good fun tool to experiment with, and cheaper than buying loads of different equipment, plus you can upgrade via the website.