Snap Ring Pliers are useful for unscrewing various pills, switch components, etc... They pivot opposite of the way normal pliers do. Harbor Freight (a US chain of tool stores specializing in cheap, imported stuff from China) has a coupon this week that I just noticed:
http://images.harborfreight.com/cpi/emails/more_coupons/wkend0502/images...
And here's the product page for it:
http://www.harborfreight.com/snap-ring-pliers-with-interchangeable-heads...