I've found some solutions:
- YQL Caching - free 2000 requests/hour/IP
- OpenKeyVal - free 64KB buckets
- IronCache - free 100MB & 10M requests/month
- GarantiaData - free 25MB in-memory cache
- Parse - free 1M requests/month
- Amazon ElastiCache - free 750h of Micro Cache Node
- Firebase - free 100MB storage
- MemCachier - free 25 MB in-memory cache
If you know more, please expand this list.
