pageoneresults - 3:19 pm on Feb 3, 2010 (gmt 0)
If I'm not mistaken, I don't think it matters these days if you use px vs em vs % vs etc. The browsers today provide a scaling function (zoom) to enlarge what the user sees in their viewport. It can be easily accessed using the Ctrl +/- keys. Yes, many users may not be aware of that but, for the users who are, we use it quite frequently on those 11px, 12px and 13px fixed font size designs. And, if you are using anything less than 11px for copy that needs to be easily read, you're asking for trouble. I hit my back button on sites that use microtype.
Personally? I've been moving to the percentage methods. One of my goals for 2010 is to go fluid on all designs moving forward. In those fluid environments I may use a blend of relative and fixed font sizing to produce the desired results. I have 3 systems here, with 2 different resolution settings. I have my viewports set to specific sizes based on what is normally available after taking into consideration scrollbars, toolbars, etc. Many of my older designs that used fixed font sizing look way small on these new larger displays which are a 21.0 set to 1366x768, both 24.0s set to 1920x1200. The higher resolutions have changed my way of thinking when it comes to using anything fixed these days.
All I can say is that I'm happy for Ctrl +/- and Ctrl+0 which puts it back to 100%.
Note: I've been using CSS min-width and max-width quite a bit these days to counter the extremely high resolutions folks are browsing at. Most websites are not designed to spread the entire width of this 24.0 display at a 1920x1200 resolution. OT, I did see a really nice 5 column implementation that I'm seriously considering using myself. :)