Cellphone Address Book Timesaver

Have you ever needed a phone number quickly, but ended up scrolling through the thousands of numbers on your cell? (Hyperbole not intended) What I end up doing is choosing the numbers I usually call most often (I stick with my top 5) or need to call up quickly. I then place the letter "a" in front of the name I assign that number. For example...
Susan
would become
aSusan
or
John
would become
aJohn.
This simplifies things quite easily.