Trying to find a module is a nightmare!
Well... It's not a nightmare to find a module you know exists but finding a module that solves your problem is very difficult and the current http://drupal.org/project/modules just doesn't cut it.
I'm using ubercart on drupal 6 and trying to see what payment processors are available.
I can search for Commerce / Advertising, Drupal 6 and perhaps a keyword of ubercart.
I get 91 modules, if i use ubercart payment as the keyword i get 119.
What's worse is that i get anything that even mentions ubercart such as lm_paypal where the author mentions looking at ubercart for a full fledge ecommerce system. The module has nothing to do with ubercart...
A partial solution could be user tagging of projects instead of the few greedy categories.
The results are too detailed resulting in lots of pagination on a search for pretty much anything, a table of modules might be nice with the option to expand for full description.