Alternative to heroku or google app engine for static files

Well, one possibility is Amazon's static website hosting over S3 together with a CNAME mapping.

The S3 latency isn't super low either. If your site is popular (so that caches would be likely to not evict your content) then you could experiment with adding Amazon Cloudfront CDN (i.e. edge proxy caching).

Sounds like you could use GitHub pages.

You could publish static files and if you change your mind later, there are a number of micro blog like frameworks like jekyll, octopress, etc.

On a related note, GitHub pages support domain mapping.

If all you want to server is static pages, why not host the site over at wordpress.com? Just set it so that the first page will not be a blog post, and the create everything using pages only having comments globally disabled. Mapping a domain to such a site is $12 per year plus the domain's yearly registration cost.

I think a similar service is also available on blogspot too and maybe posterous and tumblr.