We recently got a tip over to this It's Just Poison post about Veency for jailbroken iPhones from Jay "Saurik" Freeman, the author and maintainer of Cydia. Veency provides a VNC remote desktop server for your iPhone, allowing you to connect to the shared screen of your handheld from any VNC client (Apple Remote Desktop, Chicken of the VNC, and more).
I downloaded a copy to my iPhone, rebooted and gave it a whirl to see how well it worked using Chicken of the VNC on my Mac.
From first go, it did what it promised: offering tap-interpretation of my Mac-based mouse clicks as iPhone-sourced finger taps. The current mouse position on the Mac was echoed as a small "x" on the iPhone, so I could always see where the virtual finger was.
I had no problems launching apps, selecting buttons, dragging and so forth. Obviously, no two-finger gestures were available. There were slight gaps between my Mac-based interaction and the iPhone response, but nothing significant that interfered with work.
Video response was weaker. It had significant lag time and hangups, as you can see in the demonstration below. This means that you're not going to be able to use this as the perfect video Stevenote-style output solution. Also, any actual on-screen video from the iPod video application was not echoed at all.
The screen went dead whenever my iPhone's autolock kicked in. I was unable to wake it back up from the Mac, although I could (obviously) from the iPhone itself [update, this post at iPhone Hacks indicates you can get around this with the middle and right buttons -- thanks Alex]. One thing that did work particularly well was text alerts, which displayed whether the iPhone was awake or asleep. As Adam of It's Just Poison wrote and I confirmed, "Now I can have my phone charging in the other room, and when I receive a new txt, I don't have to get up to check my phone (or go upstairs/downstairs)". As you can see on the screenshot at the top of this article, the text displayed perfectly.
But the very best feature of Veency is this: it handles text entry. This means you can load up notes and type directly onto the iPhone. Boom!