I have been buying contracts from this really cool site that seems to be automated. I found it on eBay after winning one of their auctions. It is called mBigas.com although it redirects to mining.mBigas.com for some reason.

Anyways, they seem to be automated and have a real time queue. I have purchased contracts at 3AM and they started on schedule with no problems. They also send start and stop notifications and actually have customer service, I have emailed several questions to their support email and have gotten less then one hour response time.

Hope that helps,
cholitta