Ok, so we had some great entries for the 2-5 sentence layman's explanation of DarkSend. In the end I went with TanteStefana's submission, since it's pitched at newbies, is to the point & concise:
DarkSend is an integrated technology inside DarkCoin that protects privacy by pooling like-sized payments and by hiding who paid whom. This blocks the pattern-seeking detection methods that are used to break privacy by making them too difficult and expensive to pursue. The developers of DarkCoin and DarkSend believe they offer users the best possible privacy protection available to any crypto-currency.
TanteStefana, PM me your darkcoin wallet address and I'll send the bounty through!
1. by hiding who paid whom. => by hiding the transaction details (i.e. who paid whom)
2. This blocks the pattern-seeking detection methods => This dissolves the blockchain's transparency and pattern-seeking detection methods