Every wanted to know how to cast on for toe-up socks without having to use a provisional cast on and having to graft later? Why not try the Figure 8 Cast On? I was looking for a good illustration of this technique, but had a hard time finding anything. Here's my attempt to explain it:
Figure 8 Cast On
Okay, first you need to wrap the yarn around the two needles in a -- you guessed it -- figure eight motion. This means you go up over the top needle from the back, between the two needles and down around the bottom needle from the back to the front, back through the two needles again and you have two stitches. My picture shows a total of eight stitches -- four on each needle.
Make sure that the stitches you cast on aren't too tight or you will have a heck of a time knitting your first couple of rows. Now just pick up the working yarn and knit across the top row. Your stitches should look like the example above after you knit across all the stitches on the needle.
Flip your needles upside down -- same side facing you but the needle that you just knit across is on the bottom now. Now just knit across this needle. You will most likely have a very loose looking center row (these are the stitches that you cast on -- the ones that I told you to keep loose). After you knit a few more rows tighten these stitches across the first row toward the loose end. (Basically you will inch your way across that row, tightening as you go until you get to the loose end. Then just pull the end to tighten.) Now continue with your pattern -- why not try toe-up socks? That's what I'm making right now!