I'm not an expert on this but it sounds like a VPN client would cover your needs just fine. Sadly there's yet to be one released on the Market.
As with a lot of questions about apps and stuff, it always tends to be the same answer - 'it'll happen sooner or later'
I'm not sure if you're a coder or not, but this security-suite for developers could help you to build one if you are:
http://www.mocana.com/NanoPhone-Android.html- A secure browser
- Virtual Private Network clients to secure data communications between the device and corporate network
- FIPS validated crypto
- Malware and virus protection
- Scalable and secure firmware updating and secure boot capabilities
- Robust certificate handling features to authenticate devices, network services, and individuals to each other
You can be sure someone's working on this, just might take some time before we see it.