The music blog Stereogum has assembled a tribute Bjork's second solo album (if you don't count the jazz side-projects and the records she made as a pre-teen), similar to the ones they compiled for REM's Automatic For the People and Radiohead's OK Computer.
There are some good bands taking part (Liars, No Age, for example) but I haven't really warmed up to any of the covers yet. Xiu Xiu and Final Fantasy also participate, and both have a good track record with other people's material: there are great live recordings of FInal Fantasy covering John Cale's Paris 1919, Joanna Newsom's Peach Plum Pear and The Arcade Fire's No Cars Go; and Xiu Xiu's version of Fast Car by Tracey Chapman is fantastic (the car is stripped down to a shell and it sounds like he's choking on the exhaust).
Maybe the problem is that Bjork creates recordings, not songs, and out of her hands they're not that interesting. Checking my iTunes, I don't have too many covers of her material that work. Radiohead are competent when they cover Unravel but Ben Gibbard and Death Cab for Cutie are both too twee to handle tracks from Homogenetic.
The entire collection is available as a free download from the site, and presumably with the blessing of the artists.