The one and only time I did intarsia in the round was for this Chasing Rainbows Cap. (No pattern yet but I do hope to knit another cap and offer it as a free blog pattern this fall.) For each color I cut about 2 yards of yarn. I worked in the round with the black background color and each time I got to a new color, I did an interlock (i.e., twisting the yarns) and knit with that new color, then another interlock and back to the black which was stranded.
Here's the inside - this method will only work for narrow stripes though. As it is because the yarn for each color is pulled back to the beginning stitch every time you start a new row, it kind of puffs up the vertical stripes. I believe this is what PGR calls "zigzag intarsia" in the article referenced below. Interestingly she says to weave the background color in EVERY stitch when working the new color which I did not do for this hat. I bet her method will help the stripes from puffing up so much.
Here are some resources I've found for other methods of intarsia in the round. Some of these methods are called festive knitting or motif knitting. Some methods are considered true intarsia and some are a mixture of intarsia and stranding. Most seem to involve some sort of combo of short rows or moving counterclockwise either by purling back to a specific point or by knitting back backwards. If I've missed any good references, please let me know in the comments.
"Traditional Techniques for Creating Ethnic Intarsia Designs," Interweave Knits, Fall 2003, Priscilla Gibson-Roberts - She outlines four methods - zigzag intarsia, motif knitting, intarsia with a seam line join, and seamless circular intarsia (which looks seriously complicated). There is also a pattern, the Love Stamp Socks, which uses all four methods. I checked and this back issue is no longer available so Ebay is your best bet.
Ethnic Socks and Stockings, Priscilla Gibson-Roberts, XRX 1995. She includes a section discussing motif knitting and zigzag intarsia.
"About Festive Knitting," Heel and Toes Gazette, Fall 2001, Dawn Brocco. A back issue is available at http://www.dawnbrocco.com/ . The issue includes a pattern for Cushy Socks which use this method.
According to the Dawn Brocco article a few other print resources on festive knitting are: Meg Swansen's Knitting, Anna Zilboorg's Socks for Sandals and Clogs, and Mary Thomas' Knitting Book.
ONLINE
Meredith Davey's free Ravelry pattern for Baseball Socks uses festive knitting.
Knitty's Intarsia Fun Hat is worked in the round.
Moth Heaven has a tutorial on one method of intarsia in the round with photos. There is no direct link - check the sidebar to the left.
Let Me ExplaiKnit discusses some methods of doing intarsia in the round.
Honeybee33 discusses four methods of circular intarsia.
This is Patch the sweetie pie. She's waiting to be adopted at Petco West Side on Old Airport Road in Albuquerque. The woman who grooms the dogs says Patch is very curious and just loves watching the dogs get haircuts. She'd be a great first-time house rabbit!
You can also meet Patch tomorrow, May 9th, at our next HRS Rabbit Adoptathon between 10 am and 2 pm at the Petco Lomas (10700 Lomas NE). Please stop by to meet our adoptable rabbits and talk to our knowledgeable rabbit people. You can also bring your bunnies in to get their claws clipped or to bond with another bunny.