This site looks like it'll be a good way to decide between the million and one different pieces of gear on the market. I don't think it's fully finished yet, but what they have so far looks pretty sweet.
Interesting, though it does seem like a work in progress. For one, they don't have any sort of protection yet other than just biners and quickdraws. Also, I was expecting a site called "weigh my rack" would let you put in what gear you own and it would give you weight totals. Right now you can only "own" one of each type of gear and it doesn't give any sort of totals...
In the Reddit post in which I first saw WeighMyRack, the creator posts that she plans on adding trad gear, ropes, and other stuff. It's not particularly awesome yet, but it seems like it's got potential to be a good option for making informed gear purchases.
If only there were some sort of device that was readily available for use in the home that could give information about the mass of an object and how it is affected by gravity. I would keep it by my toilet.