Click on check it out, enter the base info then skip to enter physical activity. Create a list of activities from teh choices on the left, then save it and fill in some avg times. Then click on analyse physical activity, one of the resulting tables it gives you will list the MET value for each of the activites you selected. Its not the simple solution as it might take some time to get all the activites you want listed and you'll probably have to copy and paste then reformat it, but the info is all there.
For example, playing the drums for 60 minutes burns 329 calories @ a MET of 4, sweeping the carpets in your home for 60 minutes burns 252 cal @ MET 3.3, etc. etc. It looks like a decent list. If your client has an activity you didn't think of, you can look it up there and "get back to them."