Amazon SES Email service
The beta was announced today, the interface is somewhat limited, as this is just a beta, however, the initial prospect, is of serious interest, allowing a user to send 2000 emails per day, free of charge.
beyond that I believe it is around 0.10 per thousand emails,
This could eventually be a nice service, for now its sort of teetering on some 1988 technology, using .pl files, I am almost certain that will change, still the over all cost involved in operating a nice little system using SNS and SES would be something of interest,
considering the average cost of using other services is upwards of 20 bucks for the no frills, plain Jane featureless, cardboard type services, this would be infinitely more manageable and much more affordable.