anyone know an easy way to simulate TV scanlines using photoshop?

You mean turning something like this:



into something like this:

no, more like the way the logo of this website looks http://digitalwebbing.com/

Is there a "scanlines" filter plugin for Photoshop (serious question)?

Something like this?
An easy way would be to create a pattern for the pattern tool.
Open up a new project, say 100 x 100 with a transparent background.
Use the line tool at 1-2 pixels, and make the pattern all the way down the window.
Then go to edit-define pattern, and click ok.
Then go to the clone tool, right click, and choose the pattern tool, then chose the pattern you just made.
Add a new layer, and make the circumfrence of the pattern tool large, and just "paint" over the image on the new layer.
If the lines are too dark, you can play with the opacity of the layer.
YOu can play around with colors and distance between lines, and see what kind of patterns you can come up with.

exactly like that Hugh, many thnaks, ill give it a go . . .