to or not to specify font sizes

[gm1234]

Now this is really serious. There are some who say that a font size of 10 to 12 points would be good, some others who say that font sizes should be specified in percentage of 80 to 90% and some others who are against specifying font sizes. I wonder which one would be correct on the web usability point of view. Any help?

[Hola hoop]

10 or 12 point seems the standard but depends on what screen resol u use and will be creating the site in?
1024x768 on point 10 looks good, but also depends if the text will be coloured or set against a background?

[ScaryBinary]

I usually leave it up to the browser to pick the regular font size. Then I base all my header sizes, special fonts, etc. on percentages of that regular font, using CSS. So whatever the browser picks as the normal font, my <h1> font is, say, 15% bigger, my <h2> is 10% bigger, etc.

That way if you do eventually want to specify a font size you only have to do it once, and all your other font sizes will follow.

Also, that way if the user has some accessability issues (maybe they're partially blind or something and have their browser font set at 16 point) I'm not overriding them with a tiny unreadable font.