Any CF memory limits w/40D?

I'm needing to pick up some more memory cards for a upcoming trip and was wondering if there are any limits on what size you can use? Also, if I can use 16GB cards, would it be better to buy one of those are four 4GB cards? Does it make any difference one way or the other?

Thank you.

Four 4gb cards is moar better than one 16gb card in my mind. Worst case scenario is a card corrupts and you can't recover anything off it... at least then you're only out 4gb of photos instead of losing everything you took the entire trip on the 16gb.

I use a 16GB card with my 40D, it works just fine. I don't think there are any memory limits for the 40D at least. The 40D cannot take advantage of UDMA technology though.

During my research most people seemed to favour the multiple smaller cards over a single large card due to the loss/corruption risk.

You make a very good point. Thank you.