Not sure if it was mentioned, but I recently screened in my patio using the screentight system:
http://www.screentight.com/prod-screen-tight.shtml
Pretty simple but also pretty slick. You buy black plastic bases that are either 2" or 4" wide that have grooves in them to mount the screen with standard spline material (same way it's mounted onto screen doors). You basically make a frame around whatever opening you want screened in by cutting the black bases to length and screwing them onto the available posts. Buy standard spline material (whatever size needed for the screen type you picked) and install the screen using a screening tool/rolling knife. Then you buy the color cap you need (I used white) and cut those to length as well. They press fit onto the black base which hides the base and spline and ends up looking pretty good. I'll post pics of my project later because I'm pretty proud of how it turned out.
perks:
+ stocked in the typical local hardware stores
+ easy to install given you have a decent frame around what you want to screen in order to screw the base into
+ relatively inexpensive per piece
cons:
- found out during a hot day that the plastic pieces will thermally expand in the hot sun, so you really do need to use every single screw hole they provide you or it'll pucker out once it expands
- Color of the caps were right, but are a fairly soft plastic that scratched/scuffed easily. They're also just a dull flat finish. Hopefully in the near future they'll come out with wood prints or something to look a little nicer
- not a lot of color options, but the white worked for me