Sam also while you building your keywords... be aware of some mistakes that many people made (including me) and then they think they lost all keywords... I found that question asked on Adobe forum... I had to read it couple of times even print it, till it sinked to me, but it really helps to understand HOW the RIGHT WAY to do it...
Adobe Forums: CS4 Bridge short term memory "keyword...
and here is another one very smart question and answer...
http://forums.adobe.com/thread/484533?tstart=0