A classier kind of "hang in there" for modern times.
He doesn't really look like he wants you to have a nice day, but the sentiment is there.
Robots are appropriate for any occasion. They are neutral but friendly so you can use this card for birthdays, get well soon, congratulations on your new baby, good luck on your exams, anything!
Available at: Thinkgeek http://www.thinkgeek.com/homeoffice/supplies/e5da/ ($10) Via: Cubicle Bot http://cubiclebot.com/office-supplies/floppy-disk-sticky-notes/