In sort of a relation to Purly's post:
Recently, I've been tipped off to a Miku sampler hosted at NicoNicoDouga. It's eighty minutes of sample songs sung by our VocaloID2 heroine. Click the pic!
I recall one or two of the art pieces for the songs looking a little sketchy, but it's okay. ~_o
The mp4 of this whole thing is gettable here.
Any of the songs in the video can be viewed in full from Nico by using the id tag (combination of numbers and letters) found on each song's art. More info when you click on the video link.