Used Bitinstant today. Got my money deposited in like 5 minutes. Did two different transactions. Very satisfied.
I suggest going to your destination site though. I went to mtgox and to blockchain.info and created accounts and followed their directions.
I also tried just going to Bitinstant and doing it directly, but somehow it didn't load right and it was confusing and a waste of time.
A very important thing is to check your email account for all the final directions.
Overall A+. There are tons of locations in town where I could use cash to deposit into Bitinstant. Just get ready to fill out the paperwork. Takes a few minutes.
I also used bitinstant today and I got my money in 3 minutes. Every transaction I have had with them has been smooth except for my first one and that was resolved quickly. I have never been scammed and I know of no one that has been scammed.