The touch screen on the iPad responds to multiple-touch gestures in Safari. If you wish to enlarge the font size, simply touch the screen with thumb and index finger and then move them apart. When the font reaches the size you desire, remove them from the screen. Nice feature because you don't have to locate the font setting or guess at the size that will work best. To go back to the original size just do the opposite.
Hope this helps.
I use Readability (http://lab.arc90.com/experiments/readability/). Also gets rid of ads and sidebars. Works well for newspaper and blog articles. Doesn't really work with forums.
And it plays fine with Mobile Safari, including adding the bookmarklet? (Haven't got iPad to hand). If so, that's a pretty good way round it.
Presumably it works using the same javascript method described in this everythingicafe thread:
Increase font size in Safari without zooming
Am surprised though that there are still no font options in the Mobile Safari settings. Seems such a strange omission for a device with such an emphasis on the pleasure of web browsing on it.