Yes, download Display Fusion and set each one with a different backdrop. That will allow you to have different backgrounds on each display. BTW your setup looks pretty nice. I should have had an upgrade today but hesitated on buying an Apple Cinema Display now there back out of stock and I'm kicking myself in the ass for not buying it.
I can't speak for the USA but here in Calgary, Canada, Cable internet is whats hot. Rogers offers 50 Mbps packages, Shaw offers 25 Mbps packages for like $40 a month which I think is great (That's what I use)
Telus and a few others use ADSL but its slow compared to Cable and just as $$$ here.
The only real shit thing is our upload speed is capped here...No matter what ISP you go with here in Calgary....I am not sure if that is a Canada or Alberta thing but the most I can get is 5Mbps upload and its like $300 a month (Business connection)
You could get a fiber optic business line here but its thousands a month
It makes it very hard to host any private servers with decent speed