If you're willing to wait a few minutes, tap the Surge Drop feature
To its credit, Uber has at least acknowledged that surge pricing is a pain in the ass and gives you the option to wait out the price hike by tapping "Notify Me If Surge Ends" rather than roll over and accept the higher fare. If you enable it, it will send you a push notification the instant the surge is over, as long as it ends within the next 30 minutes.
Check if Lyft would be cheaper
If you're an equal-opportunity passenger and are signed up for Lyft as well, it's worth investigating whether a ride with the pink mustache crew is a better option. While Lyft rides are generally pricier than UberX, when a surge is in effect all bets are off. What's the Fare is a website whose sole purpose is to estimate and compare the cost of your ride in an Uber, Lyft, or taxi. There's no app version of the site, which is lame, but you can bookmark it on your phone to quickly make the call when a surge strikes.