When u get a Line 6 Pod or guitar port or any line 6 multieffects pedal u get some software whihc comes with it, and basically it means you can create + mix effects for your guitar using a really easy to use interface on yer pc, its like making a cake u can just add what ingredients you want and you create sounds. The line 6 pod is bout 200£ but i dunno bout the port bout 80£ ish, i dunno bout the guitar port but on the line 6 pod you just plug yer guitar in one end and pc on the other and it links yer guitar through yer pc and then back out through yer amp, and you can mix sounds and hear them through yer amp. You dwload the software free at the line 6 website but i dont think you can do anything much with it unless you have a port or pod.
If you wont like specific tones like Jimmy Hendrix tone you can also dwload them at the line 6 site and save them onto yer pod so you have them all the time. They are really cool the only thing is that you dont get the joy of actually having the pedal and also it can be a pain changing between tones on the pod because you have to sift through a lot of tones for the one you wont, unless you spend £200 on a midi board with loadsa blank pedals which you can then assign to the tones in yer pod.
Im not a big effects person so i stick to straight tones from my guitar, but i might get one because of the fact you can dwload a tone and the tab to go with it, e.g. Jimmy Hendrix Voodo Chile tab and tone in one, which is cool and saves a lot of time.
Hope that wernt too confusing.
Later
Josh