I recently bought the Canon SD3500IS. I like it. It seems like a lot of fun. The touch screen is huge and responsive. It is larger than my previous SD400, but still fits in my pocket.
I needed a case for this, before I could take it anywhere. I didn't want to ruin it and scratch it all up. The PSC-2050 is listed as the case for it at the website. I ordered it. I also liked the leather wrist strap I got from Canon for my previous camera (it came with the carrying case). I noticed the PSC-55 came with this same strap, which is much classier, in my opinion, than the nylon strap that comes with the camera. When I found the PSC-55 for $5 over at Amazon (that comes with the same type of Canon Leather Wrist Strap), I figured it was worth it for the strap. I also ordered the PSC-2050 (which seems to only come in Gray). I figured I ordered both from Amazon for cheaper than I could find just the PSC-2050 locally.
The strap is exactly what I was looking for. It is nice and complements the camera well.
What I did not expect was that the PSC-55 does fit the 3500. It is snug, but it fits and the magnetic enclosure is able to close just fine (I did say snug). I like this case a lot.
I received the PSC-2050 a couple days later (both items shipped very quickly and included free shipping). I don't care for the 2050 at all. I do prefer black to the gray. But I also found it to be feminine. It does have a look of a more designer purse. I think it looks like plastic. The camera does fit inside just fine. it is also a horizontal case, whereas the 55 is a vertical case. I am sure that some of it stems from the 55 being very similar to what I have had for years....and that it looks like an older lady should be carrying it. I mean, I am "older", but ...
This post is just here because I did a fair amount of searching for the Canon Leather Wrist Strap and cases for the Canon SD3500IS without finding much info.
Oh, and calling Canon was much help. They really didn't know their own products. They meant well, though.
Good Luck,
Dave