I assume voodoopad is known to you in appleblog community. it's the garden for your thoughts, as the ad says. If you visit voodoopad's website, it has some screenshots and movies. voodoopad pro has added some cool features like web server, encrypt the whole document etc.
Flying Meat: VoodooPad
Besides, you can get an iflash for free. It's a great application for you to learn a language. You can store your stickie notes and test your vocabulary and knowledge.
Loopware - iFlash
I think I can't take full advantage of this application, so i sell it in a low price.
Voodoopad pro: US dollar: $30+ iflash(free)
I got a paypal account, if you are interested in this deal, you can leave you name here and your email( instant messenger's name would be appreciated). All you need to do is transfer your money from your paypal account to mine. And I will send the serial to your email.
