Use my router as a jointer often. There are many other uses using a router with a table as well. A router table allows you to free route without using a fence, whereas with most jointers you dont have that flexibility.

On occasion I've had the need to edge join two (or more) planks on site.

Another technique:

1) set the boards next to each other as they will be joined. Then pull them apart, gapping them by about 7/8" or so.

2) Chuck a 1" straight bit into the router.

3) Set a shooting board on one of the planks to guide the router bit right down the middle of that 7/8" gap.

4) Route the gap. You'll be taking some wood off the left board, some off the right, but the end result will be that the edge of the left board will be perfect mate to the edge on the right board.

Mongo

You could always just use an actual jointer plane.

You know, the manual kind.

The edge they leave still beats any power tool.

That's one tool I never learned how to use - probably because I grew with only a bunch of rusty ones in the garage. (Gee, now my conscience is bothering me for admitting that.)

I'd like to get a jointer plane, but I never see them for sale used except at new prices or higher. Guess I'm stuck with my well tuned JJ-6