I'm amazed at how much creativity and innovation there is in this thread so far. Great stuff, guys.
Personally, the one accessory I wish had been available in vape shops when I first started rebuilding was a gooseneck magnifying lense (with an LED light you could plug into a wall or run on batteries). I spent several weeks researching them before I found the one I needed (at Office Max, of all places). The one I finally found and use every day is wonderful, but I came very close to getting the wrong one on several occasions, as not all of them tell you how powerful they are, and many of the ones available aren't powerful enough at all.
A lot of the tools and accessories we need or want when rebuilding or just cleaning stuff is hard to pin down - there are so many variations and prices and models, and not all of them are actually suited for the vaper (btw the drying rack idea from dolphin35 is AWESOME!). So it would be nice to have an accessories department in the vape store that said 'These accessories are perfect for the vaper, and at the best price we could find.' Someone mentioned a 'vaping fairy', as in 'an informed shopper' who can find the perfect stuff for you. That is something I think would catch on wildly with new vapers. Oh and someone mentioned colored rings to mark and protect tanks - they're called 'Vape Bands' and you can get them at vapeband.com.