ok, well i have a pretty old computer with a 2.6 GHz Pentium 4 processor and 1 gb ram.
I currently have a GeForce4 Ti 4200 graphics card and I'm looking for a new one but since the rest of my hardware's pretty crap, i just want something that is a bit better and will be able to sustain more.
The color doesn't matter, agp slots stand out compared to any other slot that you will find even on ancient proprietary hardware. The agp slot is usually the very top slot on the board and it can only be used for a graphics card due to the nature of the slot. Since you are using a geforce4 the slot is likely a 1.5v slot meaning that it can use any modern agp card out there providing the psu is at least 250w or better. I am a collector of hardware and after the years of tinkering, building, and researching I would know that you can use a wider verity of cards out there. If you are looking for something to just play old games and SD video content even a 6200 agp or a 9700 pro would do just fine. However look no lower than a 6600gt agp or a 2400 pro agp for a upgrade. The DX10 ati cards for agp are the best in the long run as they still have decent driver support and can run codecs on the card instead of the cpu for HD content.
If it's one of the rare AGP versions of the card, the majority of them were built for PCIE slots.
I you want to try for a very very rare agp cards then look no further than the 3870 agp and the rarest of any card produced and the most highly valued is the 3DFX Voodoo 5 6000 valued at over $2k usd on the second hand market. I know agp very well and am a collector of cards.
If you are referring to the HD 4670 1GB card over at newegg.com, then yes they do have an AGP version selling for around $124. Maybe if it is currently on sale.
It's better than your current card, but since you only have a P4 2.4GHz and only 1GB of system RAM, it will be severely bottlenecked. If you are gonna spend that much on a card then you might as well toss in another 1GB of RAM onto your motherboard.
I think a HD 4650 is more suited for your system along with an additional 1GB of RAM.