This is far and away not the best solution, but it works for me, and I can use it with only mild annoyance from a computer where I haven't "installed" it, by using an online sha256 generator. On a mac, replace "sha256sum" with "shasum -a 256".
I also suggest that if you have multiple accounts on a single site, you run "mypass user@domain.com" instead of just domain. It works fine either way, just be sure you are consistent across all sites, lest you forget your scheme.
I hope this is useful for somebody: https://gist.github.com/1013465
I also suggest that if you have multiple accounts on a single site, you run "mypass user@domain.com" instead of just domain. It works fine either way, just be sure you are consistent across all sites, lest you forget your scheme.