Samsung SPH-I500 Online User's Manual page 112

Here is a chart of how to write punctuation marks:
Writing Symbols and Extended Characters
To write symbols and characters, you simply activate the Symbol shift.
When the symbol shift is activated, a slash mark is displayed in the
bottom right hand corner of the screen, just above the Graffiti area. The
next stroke after the symbol shift is the desired symbol character. The
symbol shift is done by tapping and dragging the stylus from the top left
to the lower right corner of the Graffiti alpha area.
Section 2: Understanding Your Phone
2K: Entering Information into the Handheld Computer 109