I've not found a decent cataloging program. Whilst they all seem to record the crap details that is of no interest asa/shutter, focal length, etc, none of them can answer simple queries like "Find all the photos of beetles in Northamptonshire", well perhaps they can but the UI to input the required tagging data is hopelessly cumbersome, and they all mostly fall down unless you have the entire collection available. IOW they won't work if you've off loaded the data to DVD or an external HD.
The compromise I have is to have a file naming (location date - nnn) and folder scheme
year
monthlocation - datefinal
that allows me to manually locate the file, I then upload a downsized 1024-1200 px version to flickr. Then I do the tagging and searching in flickr. Of course it means that I've got to keep a paid account on flickr but its the best solution I've found so far.
EDIT: Also you can't have enough tags. You need to be able to add extra ones at any time, and you'll want to be able to add general and specific ones, you need to be able batch tag across photos in several locations. Most programs fall down on tagging. In one program for example you couldn't take a folder photos and add the tag 'northamptonshire' and then select a subgroup of the photos and add 'diptera' without it removing the previously added 'northamptonshire' tag. Another program wouldn't let you add the tags 'northamptonshire' and 'diptera' at the same time you ended up with the tag 'northamptonshire diptera' or 'northamponshire, diptera' and as consequence it wouldn't find either.
You'll notice in the last paragraph I misspelled 'northamptonshire'. It is very easy to do that and sometimes you won't notice for several weeks. So its useful to be able to obtain a list of your tags spot the mistakes and correct them globally.