Two easy options come to mind:

1. keep an eye on blockchain.info and take your miners down when you see Slush get a block.. it updates automatically and there should be a fairly short lag.

Since most pools use systems which discourage hopping your best bet is to leave your miners on a single pool (or point each of your individual gpus/whatever at a selection of pools) and leave them alone. If you're that bothered by the variance you should pick a PPS (pays the same per share everytime) pool.. although in most cases you'll pay a higher fee to the pool for the privilege.