Mildly off-topic, but I like the look of the model used by NearlyFreeSpeech -- a flat rate for data, no other charges. You pre-pay for your bandwidth and top up when necessary. No bandwidth used, no charges at all.

They reckon that getting slashdotted costs their members about $10 on average -- unlike a lot of other very cheap hosting services which get radically less cheap when you hit a tipping point.