Synchronize Database Structure
When you take development code live, you need to make sure that the production database has all of the tables and columns it needs.
Fortunately, you can define the table structure that you need in a component (or elsewhere) and DataMgr (if you've read my blog before, you saw that coming) can make sure that the required tables and column exist in the database.
The same approach can be used for to self-install tables for an application (I used this on CodeCop).
Watch the presentation.
View other DataMgr presentations.
If you use SQL Server and you aren't interested in DataMgr or you need to synchronize more than tables and column, Red Gate's SQL Compare looks to be a very good tool (I have personally heard it highly recommended by two different users this week).
UPDATE
I just saw someone mention that they used AdeptSQL Diff for this purpose as well. So you might investigate that in addition to SQL Compare.