I saw these Knit Klips (oh, what klever marketing) in the Patternworks catalog. I have been using safety pins to align my seams while seaming. These look like they would be much easier to use when I need to adjust and maneuver the seam alignment.
They also remind me of the little hair accessories I see little girls put in their hair.
I found the mini hair clips at Bartell Drugs for $3.50/dozen. They work great as knit clips.