Actually, you can create folders on the iPad, in the Mail app, as long as you are using an IMAP or Exchange e-mail account (it will not work with a POP account).
Here are pictures/the steps in how to do this:
<img src="http://www.ipadforums.net/attachment.php?attachmentid=8909"/>
<img src="http://www.ipadforums.net/attachment.php?attachmentid=8910"/>
<img src="http://www.ipadforums.net/attachment.php?attachmentid=8911"/>
<img src="http://www.ipadforums.net/attachment.php?attachmentid=8912"/>
<img src="http://www.ipadforums.net/attachment.php?attachmentid=8913"/>
The created folder is there on your iPad and it shows up in Gmail on the Web.
Let me know if I've left out a step ... and how it works for you. Good luck.
Marilyn
P.S. And, yeah, I wanted to play with Skitch, like The Archangel and twerppoet ... but still, they're pretty good instructions!