If you prefer small pincushions to save space on a busy/small desk this egg cup pincushion found on FaveCrafts may interest you. This is a similar process to using a teacup, just smaller and it uses an egg cup instead! This tutorial is by Christina Lane from The Sometimes Crafter.
I haven't used an egg cup in years; but then again, I haven't had boiled eggs in ages ether! Makes me want to cook some up again.
There are many styles of egg cups out there, so I imagine you could create loads of different styles of egg cup pincushions. It would all depend on your taste. Perhaps a really fancy old fashioned one with some lacy bits of stuff on the edges of the pincushion bit, maybe. Yeah. What style would you go for?
As for the tutorial: there is a picture for every step, and there are nine steps! Easy right? Give it a go!
Here is the tutorial.
[Image from The Sometimes Crafter]