I've found a neat trick which allows the font to be changed from the standard Marker Felt:
to Helvetica:
How is this accomplished? Simply add one of these international keyboards in Settings > General > Keyboards > International Keyboards:
Korean
Japanese
Add one of these non-English characters at any point in your text, and the font will switch. Now delete the character, and switch back to the English keyboard.
Note: I haven't tried all keyboards, but it definitely works with these two.

October 30, 2009 6:14 AM
Thank you SOOOOOOO MUCH for this trick!!!!! Excellent solution!