I used PayPal as well, but went for the $20 deposit, so I could get the bigger bonus. It says the $20 offer withdrawl is processing, so hopefully it'll show up in my PayPal account soon.
I'm currently trying to turn the $21 bonus into real money. I'm playing the $0.88 Bejeweled 2 games for 2 players. When I win, all the winnings gets transferred into Real Money. The $0.88 charge is split equally between the real money and Bonus credit account, so $0.44 is deducted from the real money account to play.
I'm also trying to investigate the oodles and tokens. If you have enough oodles you can can claim prizes like magazine subscriptions. They have some videos that earn you 50 oodles each under the My To-Doodles tab, in the My GSN section.