Here’s 5 easy steps to create a dotted stroke in Adobe Illustrator CS4

(1) With the Line Segment tool (\), click and drag to create your line

(2) With your line selected, go to your stroke panel, and make the weight 5 pt

(3) Apply a rounded cap in the caps section of the panel (right of the weight field)

(4) Check the dashed line option

(5) Create a dash of 0 pts and a gap of 10 pts

For bigger dots, make the weight heaver
For dots spaced further apart increase the gaps

Wah Lah. You have a dotted stroke!

For more information about creating dotted strokes, visit Adobe Illustrator online