mouse pad

MOUSE PAD:
Variation 1
Mime the use of a computer mouse then spell P-A-D.

Here's a still of that sign for "mouse."

MOUSE PAD
Variation 2
Mime the use of a computer mouse and then use a classifier to show the size and shape of a mouse pad.

MOUSE PAD (version 3)
This version uses a version of "MOUSE" combined with the spelling of "P-A-D."
Normally you sign mouse using a double movement with either the pinkie finger or the index finger.
Some people say that you should use the pinkie finger to mean "mouse" and the index finger to mean "rat."
Other people say you should use an "R" to mean "rat."  The ASL Police sometimes arrest people for using excessive initialization -- so don't use the "R" version if any ASL Police are around.  (Heh.) 
In any case, quite honestly, I feel very comfortable using the sign below (index finger version of mouse, combined with the spelling of pad).
You may notice that I am only using a single movement for the sign MOUSE.  Someone who has taken a few ASL classes but hasn't hung out extensively in the Deaf Community might gasp and tell you that you are doing the sign for "FALSE."   And I suppose if you take it out of context they would be right.  But YOU wouldn't take something out of context now would you?   The context is you are talking about computers and use a "compound sign" referring to a mouse pad.  When doing compound signs you tend to drop internal movement. So instead of using a double movement, you just use a single movement for "mouse" and then spell "pad."

MOUSE:

Alternate sign for mouse:
Instead of using an index finger, you can use your "pinkie."  Hold your finger off to one side of your nose. Move your finger sideways brushing past your nose. Repeat.  Note: you don't actually have to "touch" the nose.  Remember, some people use the index finger for this sign.