Get both of them. I have Cooliris installed for some time as an add-on for Firefox and I really like it. It does what it says but you just realize how good it is when you are in a hurry and have to find the information fast. No more opening tens of windows or tabs to find it. Just get it, never failed. Possibly the best extension so far.
PicLens is fresh from the same team and really changes browsing pictures with the browser. Get this one too. I tried with some sites and it worked just fine, but Stock.xchng needs to be worked on. Just want to see the “save to disk” feature enabled. That would really turn the page.