I’ve been a Fluid user for months and really couldn’t figure out what this feature was for. However, I had a sudden realization when I saw Todd Ditchendorf’s screenshots of the upcoming Mecca Browser.
Why is it cool? because:
iPhone/mobile webapps + normal webapps = even better web experience.
On my large widescreen monitor at home, I set up my Zimbra SSB to have my tasks from RememberTheMilk on the left and the iPhone version of the Zimbra calendar on the right. The end result is that I have a dashboard for everything I need to keep track of.