I'm not sure if anyone already does this but the (relatively) new AJAX website 30boxes.com has the ability to have its contents sync'ed with iCal. I was experimenting with it and I was able to "see" the contents of my 30boxes calendar at iCal. Pretty handy for .Mac-less Mac users like me. BTW, 30boxes is an online calendar website (think Yahoo! Calendar) that allows a user to "share" his/her calendar with buddies. EDIT: It turns out that the *other* AJAX calendar website called spongecell also has this capability! And unlike 30boxes, spongecell can import existing entries at iCal. Its nice to have freedom of choice!