1. Is it only possible to have dual channel with 2 sticks of ram, and no more?

2. Say I have 2x256mb pc 3200 ram, and they are running dual channel, can I add another stick of 256mb or 512mb of the same speed and maintain dual channel between the first two 256mb modules?
3. Is it even possible to add ram when dual channel between two sticks is present?
4. Will it hurt my memory bandwith if I did add a new stick? For example, if my bandwith with dual channel was 4000mb/s, and I added another stick of the same type, would it lower that transfer rate? What about if the stick was larger than the first two?
5. Are larger sticks of ram (256mb stick compared to 512mb stick and 1 gig stick) slower than smaller sticks if they are both DDR pc-XXXX with the same latency?
6. and final questions, Would having More RAM help out my 3dMark2001-3 scores? Also, would dual channel also benefit my benchmark scores?

Here is my setup:

Quantum Fireball 60gig HD
Radeon 9600 PRO 128mb OC'd to 425.25/326.25
AMD Athlon XP barton core 2600+ not oc'd yet
Corsair XMS series DDR pc3200 C2(nice stuff)
ASUS A7N8X 2.0 Motherboard
420 Watt PSU
DVD DRIVE
Sound Blaster live!
Linksys Ethernet card 10/100

Thankyou for your time! :)

Dual = two...that's why 2 slots are blue, & one is not...if you use 3, you're not using dual. Dual channel memory is wasted on the socket A system...you can't take full advantage of it.

Read this from Tom's Hardware:

"in theory, a dual-channel memory link does not bring any benefits since the data rate is limited by the FSB bus's bandwidth. It's fixed at a maximum 200 MHz (Athlon XP 3200+) to give a bandwidth of 3.2 GB/s. Even using fast dual DDR400 memory with an access time of 6.4 GB/s has no effect on the Front Side Bus bottleneck of 3.2 GB/s."

http://www6.tomshardware.com/motherboard/20030908/index.html

So u are saying that AMD's Athlon XP cant take full advantage because of lower FSB...but Pentium4s can? What about the Athlon 64s? they have huge FSB compared to Athlon xps...But of course Athlon 64s are not socket A, are they?

next generation SocketA

huh? What are you refering to when you say next generation socket A?