750 hours EC2 linux micro = $15
750 hours ELB = $18.75
15GB ELB data processing = $0.12
10GB EBS, 1 month = $1.00
1 million EBS I/Os = $0.10
1GB snapshot = ? (varies a lot, but less than a dollar)
5GB S3, 2000 PUT, 20000 GET = $0.79
30GB transfer ~= $4.20
The remaining items are always free.
Total: $39.96
(Marketing value: priceless)
FYI, you can calculate any bill here: http://calculator.s3.amazonaws.com/calc5.html