IKEA, purveyors of useful (and usually) imported items has one item that I think will be of particular use to those interested in the mechanical side of cycling: FIXA Tape Measure (item 402.375.57), a metric and standard tape measure which retails for $1.29 in US stores.
Bicycle measurements, especially frame dimensions, seem to be randomly specified in metric or standard units. To accommodate this and support measuring tire circumferences I bought a Stanley metric tape measure via eBay from Canada, but I thought it’ll be really nice to have this dual-unit one. Now I do, and it’s cheap enough that I don’t mind throwing it in a tool bag with other items, leaving it there to get scratched and nicked up, nor loaning it to someone and potentially losing it.