If you're tired of reading about Purgatory Comics and you're ready to finally watch the thing, you currently have these options:
Amazon Instant Video: Rental $2.99, Purchase $9.99
iTunes: Rental $2.99, Purchase $9.99
YouTube Movies: $3.99 Rental, $4.99 HD Rental
It's been submitted and delivered to a handful of other VOD services and I'll try to post them here as I become aware of them. For now, enjoy!