Staticfy provides an easy solution to convert entire sites into static html/javascript/css files. Sure, any dynamic things like search or contact forms will not work. But it can be still a useful tool.
Staticfy still on development, current realeases are just beta ones, but feel free to use if you want.
Simple install the gem.
gem install staticfy
Currently staticfy only accepts simple crawling, more complex things will be enabled in future versions.
For now you need to create a folder called output and run:
staticfy http://mysite.com
Them the generated files will be placed on output folder.