So I was playing around with OpenSolaris this weekend, via a SchilliX live CD, since I had trouble getting the Solaris Express CDs to actually boot, and I noticed that the new smf framework in Solaris 10 is using SQLite as its data store. If you poke around in there you'll find the sqlite command line client, and sure enough you can use it to mess with the databases if you're so inclined.
Of course, as with most topics in OpenSolaris these days, a little poking around reveals a blog post talking about it, and as you might expect, actually going in and messing around with the database by hand is most definately not supported ;-)
Still, it's quite nice to see companies like Sun building on top of tools like SQLite (and LibXML2 for that matter, which smf also uses) rather than implementing their own versions of the same functionality.
Note that this is at least the second major company I've seen building on top of SQLite. Apple also bundles it with Mac OS X, as part of their Core Data library IIRC.
This kind of reuse is exactly the reason I think it's great that low level libraries like SQLite are often released under liberal licenses (SQLite is public domain, LibXML2 is MIT licensed), so that commercial software can feel free to build on top of and even contribute fixes back to them when possible.