There are plenty of turbo kits out there for various Honda cars. Nitrous is popular in certain circles although I personally am not much a fan of it.

What is "worth it" to you? You can take a non-VTEC Integra, bolt up a turbo kit, add a set of higher flow injectors and a Hondata ECU to tune it, and put about 230 hp to the wheels running 9 psi of boost.