I have previously reviewed the external iPhone batteries sold by Richard|Solo. They are excellent and come in a $50 version (which I usually prefer because of its small size) and a $70 version that is larger and stores more power (which I find more useful on long trips).
Apparently, those who attended Macworld Expo last week were able to purchase the small version for only $20 and the larger version for only $40. What a deal! But there is no need to get jealous -- for those of us who did not make the trek to San Francisco, Ted Landau reports at The Mac Observer that you can still get a $20 discount on Richard|Solo external iPhone batteries through the end of the month by ordering from the Richard|Solo website and entering "MacWorld" as the discount code. Getting the small version for only $30 is a steal. If you don't have one yet, you should head over to the Richard|Solo website and pick one up before the end of the month.
UPDATE: Thanks to Tom Freeland for confirming in the comments below and on his blog that this discount does work, plus there is free shipping. Also thanks to Kevin Camden for noting in the comments below that this discount can only be used on one battery, so if you want to order both models, you have to pay full price for one of them.
