I use P3dO too - I paid up for the Pro version - but a lot of the time (i.e. when I know what I have, where it is and roughly what it's called) I use Windows Explorer, with Dimension 3D's Poser eXplorer add-on.

When I don't know what I have or where it is, then I'm in the same boat with everyone else, I think. Still waiting for the magic application that will catalogue not only my entire runtimes, but all the stuff I haven't installed yet...