As Veronica pointed out the trainer thread is a good read.

As others have noted: rollers will make your smooth. Make sure you have enough space if you plan to go that route.

Magnetic trainers are a good low-cost option, and the prices seem to be dropping all the time.

Wind trainers are reallllly loud.

Sometimes we'll get a group together (everyone brings their own bike/trainer) and we'll spin to a workout tape (e.g. Spinervals) together. Sort of a make-your-own spin class just for cyclists.

I prefer fluid trainers and music (make up my own workout) when I'm on the trainer alone.

Actually I prefer to XC ski in the winter...but that's another thread....