I've done many socks on the magic loop but never both at the same time. I know some people have started them both at the same time but I just couldn't get the hang of it. I actually had to go out and buy another set of Addis so I could start them both separately and alternate between the two. After getting a few inches done, I decided to put them both on the same 40" needle and complete them at the same time. No more worrying that they will turn out the same length. No more SSS (2nd sock syndrome).
Since I like to watch TV while knitting, I thought it was a good idea to put stitch markers between the socks to remind me to drop the yarn from sock #1 and pick up the yarn for sock #2.
This is my new project bag that I got for $12 with a 40% off coupon at Michael's. It's really cute. The inside of the bag is divided into two sections. Attached to the center divider is a flap with an eyelet that you can thread your yarn through. The sections are deep and large enough so that you can hold a skein of yarn and put your small project into the other section. There is also a pocket in the front for supplies and there are elastic loops inside to hold my straight needles.