Tim Appnel was kind enough to apply his formidable MovableType expertise to my MicroID plugin and made some significant improvements:

• There is no longer a need for an explicit context argument to the tag. The code senses the right context using MovableType voodoo (looks at the stash).
• There is no longer a dependency on Digest::SHA1. Apparently MT 3.0 and above has SHA1 code built in (see MT::Util->perl_sha1_digest_hex();)
• Other things like a localized error message and making the tag work in a recent comments loop.

I've updated the documentation and you can download the new version there.

Thanks Tim!