MyDB is a high-speed database engine that's small, easy-to-use and
portable. Works with Visual C++/C++ Builder, Visual Basic, Delphi. It
is an excellent replacement for larger database engines . Many
developers who use the Jet database engine(DAO) or BDE for their
database applications soon realize that Jet and BDE is just too big
and difficult to distribute their applications. MyDB to the
rescue,MyDB engine only deliver a single DLL(212k),or even statically
link MyDB into your applications for zero runtime files,and doesn't
need any installation and configuration, but provides you with an
interface of familiar functions to fulfill your data storage needs.
With MyDB engine, all data can be stored in only one database
file.Version 2.0 supports Long Binary field(often called BLOBs),you
can add any unlimited size files(bmp,gif,wav,html,etc.) to MyDB
files.The access is easy and speed!
Please visit the website:
http://www.mghsoft.com
http://www.mghsoft.com

As far as I know, Codebase is also light and powerful db engine.