For a time it seemed like AGP was long gone, but we're still seeing more cards put out in the aging format. HIS has produced an AGP version of ATI's X1600, and while it's certainly not top of the line, it's still a decent upgrade if your going from say, a GeForce FX5200 or something of that caliber.
"With VGA manufacturers releasing only PCI Express-based video cards, owners of AGP-based PCs were simply forgotten. Even though you can find quite easily AGP VGAs on the market, AGP users cannot find the latest releases for the AGP platform. For those who have an AGP-based motherboard, HIS is an oasis in the middle of the desert: they have just released an AGP-based Radeon X1600 Pro, which should satisfy owners of AGP-based PCs that are anxious to see new VGA models being released for this platform. Let's see how the performance of this Radeon X1600 ProAGP from HIS is."
Of course, if you're looking for something a little more robust, you could always look into Nvidia's GeForce 7800 GS AGP.