Aside from checks and cash, what do you accept for payment - ie, Paypal, credit cards, Google Checkout...?

We have Google mainly due to the robo-call side of the business but I don't know how its looked upon in the video industry.

Also, do you provide any 5 net 30 incentives (pay within 30 days and get 5% off)? I've read about many freelancers getting screwed over because large clients put off paying them for several months.

I accept Paypal but almost all of the corporate clients I have ever done work for paid or pay by check.
It used to be 30 day pay was common, some even sooner, then it went to 45/60. I have 1 client I've been waiting going on 90 days. Guess who won't I won't be working for until they pay up. It's not a hugh amount either but 90 days is too much. No I don't offer 5 off for 30, if I'm going to discount the job I do it upfront in the pricing. I had some long time clients and we had a pretty good understanding.
Today it seems different.