splitting large patch files into smaller ones

I recently had an occasion to take a rather large git-diff patch, and split it into smaller chunks. This was so I can more easily import the patches into guilt, then reorder, rename, shuffle, and join individual patch snippets into logical patches (i.e., one patch per topic).

I was looking around for a tool that would allow me to split a large patch file into individual snippets and couldn't find one. So I wrote one in perl. It takes a patch file and creates individual small files, one for each combination of a filename listed in the patch, and a patch snippet (starting with an '@@' line). Each '@@' snippet gets an index number and a new filename, prefixed with the appropriate header ("diff ...", ---, and +++ lines) so it's a valid patch file on its own.

Questions:

1. Does anyone know of such a tool, perhaps written in C for better speed?

2. If not, is there any interest in such a tool?  If there's interest, I'd
   be happy to cleanup my perl script and contribute it to
   git/guilt/whatever.

Cheers, Erez.