I'm coding a resource site around a fairly large directory database, and I'd like to make some kind of in-site search available for my visitors. I'm debating between whether to use Google's premade site search (which I can drop right into my template) or coding a custom search that accesses the database directly.
Obviously, the custom search will take alot more work - but if Google can't offer close to the level of results that a custom can, I'll do it. What do you think?
Use the google search. It's what they do.
If you don't want to be dependant on them, then look at one of the free search utilities such as htdig. Or a plugin to whatever website engine you're using.