Is there some Unix util that will allow me to grep multiple files with little typing?
You may find your shell helps you. For instance, in zsh, you can do
grep foo **/*.pyprovided the number of .py files doesn't exceed the maximum number of arguments allowed for a command (64k?). Note you can qualify the file globbing e.g.
grep foo **/*.py(mh-5)which will give you everything modified in the last 5 hours.