You betcha, I could. That is a tutorial that I really should set up. To add a 1 pixel border in Photoshop, follow these steps:
Create your userbar.
After you are finished, add a new layer on top of all the other layers. You can do this by clicking on "Layer", then "New", then "Layer" (or you could use the shortcut keys "Shift" + "Ctrl" + "N").
Make sure you have the new layer selected, then press "Ctrl" + "A" to select the entire image.
Next click on "Edit" and then choose "Stroke". This will open up the stroke box.
In the stroke box, make sure it is a width of 1 pixel (you can change this if you like, but most userbars have only a 1 pixel border), choose what color you want the border to be by clicking on the colored box and selecting your color, then make sure the location is marked "Inside". Blending should be normal, and Opacity should be 100%...leave these on this setting.
Then just click "Ok". This will apply a 1 pixel border to the image.
Press "Ctrl" + "D" to deselect the image and you'll be able to see your border. Then just save the image like you normally would.
Let me know if you have any questions, I'll be happy to assist in any way I can.