There are various public images available but they all have stuff in there I don't want!
I have built a 1Gb image of CentOS with the minimum base feature-set... i.e. only the packages you get from typing...
yum groupinstall base
Since I'm not American I can't sell this using Amazons DevPay program so I'm offering it here... since no-one replied to this post I figure I'm allowed!
I have a CentOS filesystem file (which you can mount via the loopback filesystem) which can be booted within EC2.
To use the file as a private AMI three further steps are required...
Each of these are commands from the AWS tools; all of which I'm happy to do for someone but they would need to handover some secret AWS credentials (it's your whether you're comfortable with that or not!).
If you're interested contact me, I was thinking about £10 (\$10->\$15USD depending on the exchange rate) was a fair price... obviously you'd paying me for the my time, not the linux or CentOS distribution as they're free and opensource :-)