I don't know what types of gears you are looking for, but a good place to start is here:
http://www.3dcontentcentral.com/Default.aspx
or some gear manufacturers have models available on their web sites.
Larry

you may want use a gear design software for doing this:

• http://www.emachineshop.com/mac...gn-Software/page506.html
  
• http://www.fairfieldgeardesignsoftware.com/
  
• http://home.swiftdsl.com.au/~gears/gearcad.html
  
• http://www.ur-sports.com/gearcam/demo.aspx
  
• http://www.hobbing.com/index.html
  

hth,
Norbert

Thanks for all the great ideas. Between them there are a few good ways of drawing gears.
I actually took a stab at it as well, using a straight line instead of an involute for the gear shape. I will take a look at modeling the involute.
Here is my simple way of modeling a gear.
Draw concentric circles for the root diamter and the outside diameter.
Draw a midpoint line centered with Y equal to half the tooth thickness and X equal to sqrt(ptich diameter^2-Y^2) with angle minus the pressure angle with length long enough so that it intersects both circles.
Draw another midpoint line with Y=-Y and the angle positive the pressure angle.
Select the circles. Use trim tool to trim lines to circles.
Select the lines. Use trim tool to trim the outer circle.
Select the lower gear edge and the gear edge that was part of the outer circle.
Use the polar duplicate tool to copy the select edges at angle 360/(number of teeth).
Use the fillet tool to fillet the edge intersections starting at the top. The inner circle will disappear where it is not needed when the fillets are added.
Delete the bottom tooth edge and the second tooth edge at the outer circle.
Select all the tooth edges.
Use the polar duplicate to make the number of teeth with a rotation angle of 360 degrees total.
Select the outline and group it.
Extrude the outline into a gear.
I'll have to work on doing the involute, but the above process is pretty quick to do.
Thanks. I will have to look at all the gear design programs suggested. For now all I need is a pretty picture.