Samsung SPH-M610DAASPR - Manual (Page 75)

Section 2A: Phone Basics 49
Phone Basics
To use Two-Touch Dialing for speed dial locations 10-99:
1. Press the first digit.
2. Press and hold the second digit for approximately two
seconds. The display confirms that the number has been
dialed when it shows the name and number of the
speed dial.
Note: Speed dialing is not available when you are roaming.
When you are roaming off the Nationwide Sprint PCS
Network, you must always dial using 11 digits
(1 + area code + number).