Originally Posted by root
you could each just keep a personalised homepage on a site.
wait for it to be indexed by google and then search using google.
that's much easier than having a database field that needs to be hugely large to categorise interests -or a restrictive list.
That is actually a very elegant solution, provided you don't mind everyone's information being accessible by the public. It's similar to a Faculty section on a university website. However, from the OP question it sounds like privacy is restricted to members-only.
This may be an obvious point, but an organisation of that size should have some sort of centralised personnel database which would therefore lend itself to storing this sort of information securely. However, such solutions are typically very old (technologically speaking - e.g. SQL) and inflexible, not to mention very
custom - so your users would not find it intuitive and familiar to use.
Considering the above points, I'd recommend you take a look at the huge
variety of pre-built software/service packages available at www.turnkeylinux.org
- take your time to read through the descriptions and then have a go at using them. They are available as virtual machine appliances so provided you have Virtualbox/VMware (or other VM management software package) installed you're ready to go in under an hour. They all come with very good documentation and hopefully should suit what you need (oh - and they're all free!)
Once you've found a package that meets your requirements I'd suggest familiarising yourself with the configuration options to ensure you can secure it to 'members only' effectively before deploying it to an operational server in your organisation.