How do I run VNC (any flavor) from the iPhone (Jailbroken/not jailbroken)? I would like a solution to remotely manage my PC from my iPhone, I could even use an RDP client? (I'm running a number of OSes Windows XP and Windows 7 and Hackintosh 10.5.6 but I'm interested in remotely managing the Windows XP box first!)
Check out Mocha VNC. The lite version is free.
LogMeIn has an iPhone app, though it's not free. I haven't tried it, but I'm a fan of LogMeIn (free) in general. Secure connections to multiple computers from any browser, sorts out firewall and port problems itself, handles dynamic IP addresses, multiple users can have different permissions -- all in the free version.
(As always, be wary when using public PCs.)
Update: There is now a free version of the LogMeIn iPhone/iPad app.
You can also use Zinger-Soft's iSSH for tunneled VNC or X server over SSH. Works great even with RSA Key encryption instead of SSH passwords.