Saving money: using a 64bit Ubuntu VPS instead of a 64bit Large EC2 instance

I need to frequently run a 64bit Linux web service (commercial app, not available as a 32bit app). Unfortunately, small EC2 instances are only available as 32bit. I ended up using a 64bit VPS instance (I use RimuHosting, but I think Slicehost also has low cost 64bit VPSs). Saving a lot of money over the long term :-)