atm i use picsa but mianly for it's RAW viewer to sort after a shoot i'm developing my structure in Extensis Portfolio if your serious about it something like extensis is the go totally customisable and searchable all my images will be tagged with key words of who is in them and any prominant brands activities so you ca search for say DC shoes and any shot that has a DC shoe logo prominant will show up there are heaps of other features check out
I recomend you watch the first video here[/img]http://www.extensis.com/en/products/Portfolio7_Video_Demos.jsp#[url]
it's a tutorial but it gives you an overview of the product
extensis also has a server so you can have it on you server and just have clients this way you can build up your database on a mirrored secure server and just access extensis from your clients
personally i'm using this as a
model to develop my own php/sql database system that will be more my style run from a web server on a dedicated photo box but because i'm pretty slow with non work software dev it'll take a while so extensis it is in the meantime[/url]