The only way for speeding up a transaction is to put a bigger fee. There are some website that recommend a fee according to the last block stats, and there are also some wallets that calculate the ideal fee, but always check the proposed fee as sometimes the algorithm fails and suggest an extremely high fee.

Also some wallets allow the replace by fee option, which lets you increase the fee without waiting for the transaction to get out of the mempool. Multibit does not offer this option yet.