I've been trying to find the best way to do this, too.

Julie, using the white vinyl for the floor of the shot w/white seamless background is what I am going to switch to! This Christmas was a nightmare, I used the huge roll of white, unrolled so the dogs/people were on it. PITA!

I have found that the "matte" versions of vinyl (about 5" wide) from Joanne Fabrics are working really nice for single/couple shots. Made the mistake of getting a blue vinyl that had some shine to it to use for the Humane Society shots I do...will be taking that back and getting something else as it looks like total crud. I went thru a roll of blue seamless with the dogs there in about 2 months, so I need something to last a bit longer. Plus they don't like the sound of the paper, the vinyl is quieter and there's no wrinkles to deal with.