Wow.. lots of info.. thx folks!! Well, I guess part of the problem is that I'm cooking at a location I'm not familiar with (and too far to go to for a casual look see), so I don't know the arrangement of the cooking area, etc.. I've been told it only has one oven and that the grill that I'd have access to is a Weber A series. Looking at the A series, I can see that it only has 2 burners and isn't that large so I'm not so sure that indirect heat cooking in the grill would even be possible (though it does have a built-in thermo). So it looks like the oven it will have to be, unless I get there and am pleasantly surprised otherwise, in which case I'll try the grill... and yes, I have a Polder probe so thatll remove the guesswork on my part. I understand the whole 41-140 range.. went to culinary school and am doing catering on a low key part-time basis... I've done parties like this but the first time I've had to deal with HD, grilled items AND a roast.. the roast is obviously throwing me off.. I was going to buy a bone-in roast, and then just remove the bones prior to service (keeping them for my lil treat)... WAH LA!! Boneless roast... served in slices with optional sides of a wild rice stuffing (w/ craisins, golden raisins and pine nuts) and a mango/jicama/cucumber salad with citrus vinaigrette... something to keep it all lite, and prob the option of Au Jus or a horseradish cream sauce on the side for people who want.. This isn't meant to feed everyone, I'm hoping for it to feed 25-30 people at about 1/2 lb a slice.. considering that for 4 hours before that, they will also be feasting on 8 different Hor D'oeurves (HD) (all with some starch involved). The rest of the party can feast on grilled salmon (pre-marked, held in fridge and finished in the oven) and the host is buying several pre-done peruvian rotisserie chickens. But I think I understand my choices now... a) if I have access to a grill that I can use indirect heat on, then use that... If no indirect heat is possible, I can consider inverting one sheet pan and then placing another one w/ a rack on top and put the roast on that? (assuming the roast even fits into it the grill) b) Perhaps use the grill at high heat to reheat my HD's instead and use the oven to slow roast the sucker.. I have a feeling I won't be able to bring it down to a temp of 150, lets say 200-225 is more likely.. should I expect something like 22m/lb? So for a 18lber.. 6.5 hours roughly.. Any other options? The overnite can't be done since I won't be there until early early morning.. Thanx guys (and gals!)!! I've been reading this board and searching through it for ages and love it.. first time I'm posting and I love all the serious answers.