I've seen in a video on youtube how someone used a double-resolution on a geforce 7200 card, but he doesnt explain how he got that in his list.
Now I have been able to create double monitor resolution and get in in the list within FSX even, but with me it doesnt work.
1) Get a Matrox Box
2) Get another Nvidia card running in SLI, so that you can enable "Surround"
3) Get an ATI Eyefinity card
I don't think there are any other options.
I agree with Snippy and add this, No matter how much duct tape you have on hand, you are just going to struggle and end up frustated. Out of the above three suggestions Matrox is the simplest route and is very user friendly. If Matrox slowed my FSX by by one or two frames per second, I haven't noticed yet. My sig is a Matrox dualscreen shot very heavily compressed to fit in the sig space but it's still not to bad. Matrox software doesn't ask your vid card to do any thing more than it was doing, other than use a higher resolution. Once your vid card spits out the info through its output port (VGA or whatever), it has no idea whether