I brought my Holga 135 with me on my trip to Costa Rica and used regular ol' 400 ISO film.
Most of the photos turned out blurry, or overexposed. Such is the risk with using what is, essentially a toy camera, experimentally. Even though most are blurry, with a little bit of darkening with photoshop on some, it actually led to some really awesome effects. Almost ghostly!
(This one reminds me of a David Hamilton photo)
(this one, and the one below, are the only two that were not edited whatsoever)
I love film.