A higher gear should do the trick. The standard technique on roadsters is to shift up a couple of gears before going into a standing position to crest short hills. Ideally, you should be able to "dance on the pedals", as they say.

It's very odd to me to see so many people buy 24-speed mountain bikes and never use the gears. I see many of the students here at the university actually get off and push while going up hills!