1991 4 Cyl Camry Performance Increases?

[TNCamry]

OK I know this will be embarrassing, but here it goes-- My parents bought a 1991 4 Cyl Camry new and now I am using it for a second car for commuting. It runs great- 130,000 miles on it and gets a solid 30 mpg. Everything still works and it doesn't burn a drop of oil. BUT- is there anything I can do to increase the performance a bit? I think it has 130 HP but it could really use a bit more umph :o for those uncomfortable merging situations on the Interstate and big hills are a chore. Turbos? Special tuning? Don't want to drop in a 6 Cyl or use nitrous and a Hemi is a bit large...