Visit the Russian Consulate website. Things have gotten MUCH easier for a US Citizen to get a business visa. And the new 3-year Visa (as of Sept 2012) makes it even easier.
And you want the 3-year one ! There's less documentation required and it's simpler to acquire.
As a legal resident of Thailand (with a US Passport) I got mine in BKK in 5 days for $160.
ONLY at the Mongolian->Russia border crossing did anyone take notice. And that, according to local officials, was because my Visa had been issued in BKK to an American.
Good luck !
Orange, it's the new black.