have you seen the ippity stamps from unity?! you can pick a chick and order. it's quite easy.

i used my ippity stamps in a project life page. see:

 
soooo...i have three kids, in multiple sports. i bring my project life stuff with me to practices so i can work on them in the car or at the gym or ball field. i pre-stamp my unity images:

 

and then put them in my bag-o-tricks and bust them out when i have a spare minute.
 

if you have not tried project life yet, i HIGHLY recommend it!! :)