I keep a page on there and I like how it gives me a quick way to link together my Internet credentials (so-to-speak) without much clutter. As for whether people actually check it out, that's another story. I tend to keep it listed as my "homepage" though for sites that list that information on my profile.
I would have used it, but it always said the username I wanted was unavailable (despite the page saying "This name is available!").
Then last month it suddenly became the page of a SF-based developer, which seems to happen all the time for 'unavailable', but unused, names. Pretty annoying.