Still a vaild coupon. I used it a few days ago to get (2) 512MB SODIMM's for my new Inspiron 8500. To use it you add the items to your cart and then above your order you'll see a box for coupons, just type in ANAND and then check the box next to it then update your cart.
I had ordered the RAM from Crucial because it came out to be around $30 cheaper, but it kpet locking my laptop up (4 times in 4 hours). Since I got the Mushkin no lock-ups, so now I know who to trust in the future. BTW I had bought RAM for my old Inspiron 8100 from Cruicial and started to get lock-ups from that one as well, so now I just figured out it was the RAM 2 years later.
Also, I don't think this will get locked or deleted, so just keep using it as long as you see the coupon on the main page of Anandtech.