I'm happy with some of the tweaks I made to my tile generation setup. I mentioned it on IRC and one person asked for a writeup (not that it's all that complicated), so here it is.

I really like TileStache for tile generation (plus it's a nice tool for turning WMS and ArcGIS REST interfaces into tiles, too). It does on-demand tile rendering with a selection of caching strategies, including caching to S3.

The nice thing about S3 is that it's cheaper, both storage- and bandwidthwise than my webhost. The problem I ran into is that TileStache's caching, for flexibility reasons, doesn't know anything about the particulars of each cache mechanism. It just knows that if a tile is cached, it reads it out of the cache and serves it to the client, otherwise it renders the tile and caches it. That ends up double-billing me for each cached tile: once from Amazon when the tile is read out of S3 and again from my webhost when the tile is sent to the client.

All I did was add a check for the tile on S3 before calling TileStache and, if it's already cached, send the client a redirect to fetch it from S3 directly. The script is on pastebin.

I also hacked my copy of TileStache to use reduced redundancy storage for cached tiles. If they get lost, they can just be rerendered, and it's cheaper this way.

Incidentally, I really like my webhost. If you're looking for cheap, pay-for-what-you-use hosting for a small to medium site, you could do worse than NearlyFreeSpeech.NET.