You can use UFASoft Coin. Which is a multi currency client and miner. Also it's open source.
The supported currencies are.
- Bitcoin - BTC
- Bitcoin-testnet
- Namecoin - NMC
- Litecoin - LTC
- PPCoin - PPC
- NovaCoin - NVC
- TerraCoin - TRC
This will essentially keep all your wallets in one application, so no more have 6 different wallets and clients. Then forgetting to start certain ones.
Just a side note regarding the performance of mining directly from the program: I have found it to be slower, around 10-30% slower than other miners.