What is the collective opinion on thank you notes for job interviews?

I had a GREAT job interview today, and I know I should send a thank you note, but I’m curious if these have mostly moved to email, or to typed and mailed, or if they should still be handwritten, and if they should be handwritten, should they be on a card, or just on notebook paper? I have email addresses for 2 of the 3 people with whom I met, but I should have time to snail mail something as well as I don’t expect a decision on 2nd interview to be made until next week. I applied to this position on line, and set up the interviews over the phone if that matters.

The company is an older, family run company, but they embrace technology, in fact part of what this person will do will be to help with implementing new Enterprise/Accounting software. I met with the GM, the Owner, and the implementation consultant/interim Controller, for the Controller position. Part of what gives me a heads up is being modern and tech savvy, so I don’t want to come off too low tech, but then again, I don’t want to come off as too impersonal if that’s still the standard expectation.

I’ve been out of work since early February 2009, so I really don’t want to do anything to mess this one up, so any suggestions on what form it should take, what specifically I should say in the letter, etc. would be greatly appreciated and considered.