My brother-in-law, who is a pharmacist, turned 40 a few weeks ago.  My sister had this cake custom made for the occasion.  It says:

MERWIN DRUG

Rx: Old2Day
#40 tabs

Take 1 daily to get you through next 40 years

Warning: If not taken daily, may cause temporary lapse of judgment and purchase of corvette!

So far, no purchase of a corvette has been made.

Previously on BC:
NES Controller Cake
Cake Wrecks
Optimus Prime Cake
Mario birthday cake
Nintendo! It's a cereal and a wedding cake?
Mac Mini Birthday Cake
iPhone Birthday Cake