The default Movable Type bookmarklets break in Apple's Safari browser. Jen Segrest has a Post-It! bookmarklet that works properly. Over at randomWalks, the bookmarklet has been slightly tweaked to take advantage of selected text.
Note that these also seem to work with OmniWeb, which is now back on my browser radar, since it uses WebKit, the Safari core. OmniWeb now seems sprightlier and still as beautiful as ever. Downside is that it doesn't do tabbed browsing. Way upside is the rediscovery of shortcuts in the URL entry field.