First, my apologies to those on dial-up. This is my first time doing a tute and I've tried to be thorough. Some of the pics are just additional "this is what it'll look like at this stage" pics, so I'll leave those as thumbnails in an attempt to speed up download times.
This is "crochet on the double" also known as "cro-hooking" and probably a bunch of other names.
Basically, it is like Tunisian crochet (aka afghan stitch), except that you use two colours and a double-ended hook.
I got my hook from Mary Maxim. For this tute I used Bernat Satin yarn which calls for a 5mm US 8/H hook. I use a cro-hook slightly bigger than called for, in this case, I used a 6mm J double-ended hook. When doing regular crochet stitches I usually use a hook slightly bigger than called for (in this case, 5.5mm) so experiment with hook size to see what gives you the best results.
Start with a base chain of exactly as many chains as you need stitches. I did ten chains, and ended up with ten stitches.
The loop on your hook at the end of your chain is your first loop in the loop row. Insert the hook into the next stitch and pull up a loop.
Continue in each chain, pulling up one loop for each chain stitch. (10 loops on hook)
Move the loops over to the other end of the hook.
Turn.
Add the second colour by pulling a loop of it through the first loop on the hook.
Work the loops off of the hook by pulling the second colour through two loops at a time.
(So, yo, pull through 2 loops, yo, pull through 2 loops, ... until you have only one loop left on the hook, it will be in the second colour)
The loop left on hook counts as the first loop. Insert hook into the second vertical bar left by the first colour.
Pull a loop through. Do the same for all vertical bars. (10 loops on hook)
Move loops to other end of the hook.
Turn. (Keep an eye on the yarn leading to your yarn skeins. If you're careful about how you turn your work, you can keep things from tangling.)
Pull the first colour yarn through the first loop of the second colour.
*Yo, pull through 2 loops* repeat between *'s until you're left with one loop of the first colour on the hook
The loop on the hook counts as the first loop in the next row. Insert hook behind the second vertical bar in the previous row (second colour)
Continue until you've lifted a loop from every vertical bar (10 loops on hook)
Keep going until you get to the length you wanted.
Finishing:
I finish with a row of sc worked into the vertical bars of the previous row in whatever colour is on my hook when I'm finished the last row. I'm not completely happy with how it looks, but it works. If anyone has better ideas about finishing, I'd be interested in hearing them!
Insert hook into second vertical bar
Pull through a loop. Two loops on hook.
Pull a loop through the two loops. Sc made.
Finished, yellow side (second colour)
Finished, red side (first colour)
Questions? Comments?
Join the CAL for this stitch here:
http://www.craftster.org/forum/index.php?topic=238605.0ETA: lindseycore and a Tunisian crochet tutorial suggests to finish with a row of slip-stitch. I think that would look better!
) advertising by donating a challenge prize! 
