How does one send and receive Mastercoins? I don't really understand how the Mastercoin mechanics work, do I need a special client when operating with Mastercoins? And how should I proceed with the initial investment?

If I were to recieve MCSs would I use my BTC wallet and if so how do I know the amount of MSCs in my address?
To send or receive MSC, you only need a Bitcoin wallet when you have control over the private keys. so web wallets don't count