Gauge does not matter as much on a scarf, so the yarn and needle size you choose to use has some flexibility. The sample shown is knit on size 5 needles using Knit Picks "Gloss" DK (found here: http://www.knitpicks.com/cfyarns/yarn_display.cfm?ID=5420190).
Materials needed include:
Size 4, 5, 6 or 7 needles
250-300 yards of Fingering, DK or Sport weight yarn
Yarn needle for working in ends