Do you use source control for your database items?
I absolutely love Rails ActiveRecord migrations. It abstracts the DML to ruby script which can then be easily version'd in your source repository.
However, with a bit of work, you could do the same thing. Any DDL changes (ALTER TABLE, etc.) can be stored in text files. Keep a numbering system (or a date stamp) for the file names, and apply them in sequence.
Rails also has a 'version' table in the DB that keeps track of the last applied migration. You can do the same easily.
Must read Get your database under version control. Check the series of posts by K. Scott Allen.
When it comes to version control, the database is often a second or even third-class citizen. From what I've seen, teams that would never think of writing code without version control in a million years-- and rightly so-- can somehow be completely oblivious to the need for version control around the critical databases their applications rely on. I don't know how you can call yourself a software engineer and maintain a straight face when your database isn't under exactly the same rigorous level of source control as the rest of your code. Don't let this happen to you. Get your database under version control.
The databases themselves? No
The scripts that create them, including static data inserts, stored procedures and the like; of course. They're text files, they are included in the project and are checked in and out like everything else.
Of course in an ideal world your database management tool would do this; but you just have to be disciplined about it.