I bought one of these insulated mega sized mug at my Weight Watchers meeting. I saw all these ladies carrying these mugs and I finally got one, too. It's great. It holds 32 ounces; is insulated so it never sweats; has a sliding open/close top; and a big plastic straw. The only downside is the cheezy Weight Watchers logo on the side. Seriously, do they think people want to show that they're on a diet?
I squeeze a half of an organic lemon, add 2 or 3 Splenda packets, ice and water to fill to the 32 ounce line. Awesome! I just top it off and add the other lemon half when needed. This is so much better tasting than a prepared mix and good for you, too. I try to drink one before lunch and one after.
Find your local weight watchers ( about $6.00) or find on eBay ($10 and up).