A quick printing boat with keyring loop for giving to friends as an example, I noticed that people understood 3D printing best if they had something they could relate to / use
The photos here show the keyring boat printed using a Printrbot Jr 0.4mm nozzle in PLA using 0.3mm layers and pretty much solid infill.
Took 31 minutes to print at full size. Optimise the fill and you could cut that down to 20. If you reduce the size of the boat to 2/3rds you can still use it with a cord to attach to keys but the stubby seat / cylinder might turn out blobby.