I use a high pressure splitter, which I mounted onto one tank. It has an acme attachment, and a male "disposable" tap, to which I attach a long 12' hose, to go to the grill:
http://www.adventurerv.net/degrees-propane-tee-only-camper-p-1307.html
http://www.amazon.com/Camco-59033-Propane-Supply-Hose/dp/B0014EAWPY/ref=pd_sbs_sg_5
(also comes in a kit with both parts together, but I found it's a little cheaper separately)
This works perfectly. I've since (at DW's request) purchased one of those portable campfires (campfire-in-a-can, it's actually really nice!) Gives a campfire feeling, while being able to regulate output 100%, which is nice with twin 2 1/2 year olds. Plus, you can just turn it off when you're done, no need to worry about wood burning down or what have you. Gives us options.

For this, I got another tee, and another hose, so I can keep both the grill and campfire plugged in and away from the TM. So far, so good, and I don't need to pack the extra weight of another propane cylinder.
Just FYI, the low pressure is like 0.5 psi (11 inches of pressure, or something like that.) Some grills can be converted, I have read about people converting a Baby Q to low pressure with varying success. I have a low pressure T put in by my dealer, but haven't been able to find anything to use with it. The portable campfire would, but then there's a hose length issue, and I wanted it to be far from the TM, so I opted for the high pressure solution (as suggested by the C-i-a-C engineer). 24' of hose, and it's perfectly usable.
