I recalled something I had read about knitting stripes and applied that method.
It works this way: Begin with one of the balls of yarn. Do your Judy Becker's magic cast on (see videos on the net, especially check out Cat Bordhi's good videos on knitting). At about the 4th or 5th round knit the first three needles, but not the fourth needle. Start the new yarn at the first needle of the next round. Knit that first needle using the new ball of yarn. Call that ball the "Leading Yarn." Now knit the fourth needle of the preceding round with the first ball. Call that ball the "Following Yarn."
Continue in that manner, knitting the second needle of the round with the Leading Yarn, then the first needle with the Following Yarn, etc. The yarns never have to cross and the result is stripes without "joins."
The left over bits are to the right of the socks. I knitted half of each ball into the first sock, saving half of each ball for the second sock. The half way point was determined by weight. When the balls had 25 grams left I bound off the first sock and started the second.
This was a fun, rewarding project. I intend to wear these myself, rather than "gifting" them out to someone else. The ribbings look quite tight, but stretch out to fit my legs just fine. The final touch on each sock was using Jeny Staiman's Surprisingly Stretchy Bind Off. You can find a good tutorial on that technique from Cat Bordhi if you just google it.