Ok, I've go the chance of testing a friend's turbo trainer ("try before you buy" sort of thing) and I have a few questions for forumites if you'd care to share your experiences:

Are they any good?
Will sessions on this aid with the running?
Are there different types of TT that I should go for?
And (most importantly!) does anyone know where I can get one resonably priced?

Ta v. much.
J