I spent ages looking for one those things some years back, and while they existed in the part reference on Canon's website, no dealer or distributor would admit to ever even having seen one, never mind stocking it.

I guess the sitution has changed. Funny, as the most recent Canon camera I got (an S90) no longer has the facilities to use such an adaptor

Well, as they are apparently available, the problem originally stated could be solved either with one of these plugged into the mains, or via the adapter to the PSU I previously mentioned.

pca