Been playing with using XMLHttpRequest for accessing a WebDAV server. Fine on Firefox, but Safari won't send anything other than 'GET' or 'POST'. Checking the XUL reference, it seems that Firefox supporting the WebDAV methods is accidental. I guess I'll have to make a filter that converts GET <url>?method=PROPFIND and POST <url>?method=PROPPATCH ... to PROPFIND <url> and PROPPATCH <url> server side. Which is a bit naff.
The canvas API in Safari I stumbled across trying to find a definition of the XMLHttpRequest API (and don't you just love the random capitialisation of XMLHttpRequest?) looks cool, but that would mean targetting only Mac users at present, at least until Firefox 1.1 happens next month.