Sometimes grep or TextMate's find can take a long time so I decided to give a mini search engine a try using repoze.bfg, repoze.catalog and Pygments. The result is that it works rather well and is very fast. The catalog ends up being rather large once you add groups of packages from Plone and such so this ends up making the RAM usage be very high unfortunately.
It gives you the ability to easily search methods, classes, filenames and full text and then give allows you to view the file with pygments.
You can take a look at search.nathanvangheem.com to see it working with repoze.bfg and Plone 4 being indexed.