Preferred plugin installation method

For anyone who cares to comment, how are you installing plugins (from github, 99% of the time) into your projects, and why are you using the method you're using? I'm assuming you're using git to manage your code.

Specifically, are you doing something like script/plugin install git://github.com/ajsharp/mass_assignment_murderer.git (assuming you're using rails 2.1)? Or, are you doing something like git submodule add git://github.com/ajsharp/mass_assignment_murderer.git vendor/plugins/mass_assignment_murderer? Or are you just doing a git clone or something? (And yes, that was a very shameless plug for a little plugin I wrote)

I've never really gotten a good feel for what the best practice is for plugin management, so your answers and input are greatly appreciated.