OmniDB lets you create a distributed layer of cache for your database.
The cache and database are both configurable.
Currently the cache is configured to use memcache.
The database is configured to use mysql or sqlite.

												              ____________
																		 | Remote DB  |
																		 |____________|
																				  ^
																					|
																					|
											          _________________________
															 | Distributed Cache Layer |
															 |_________________________|
																				  ^
																					|
																					|
				-------------------------------------------------------------------------
				^												^												^												^
				|												|												|												|
				|												|												|												|
 __________________ 		 __________________ 		 __________________ 		 __________________
|Client instance 1 |		|Client instance 2 |		|Client instance 3 |		|Client instance 4 |
|__________________|		|__________________|		|__________________|		|__________________|