The Lensbabies are a great idea at $25. At $100, they're a bit more than I'm willing to spend for a "Holgaesque" look.
I say...save yourself some money. Get a cheap loupe or other small lens, some flexible tubing, and assemble it on the front of a camera body that has a focal plane shutter. Voila...you're an artist!
Seriously: If you like the look, check out this:
(Of course, he took the "expensive loupe on an expensive camera" route...but you get the idea.)