I'm not sure how long these have been out, but this is the first time I've run across them, so I had to share the news....
Barely There (as in the really lightweight, soft microfiber panties and bras) has a line of panties called "Jeanious"... thongs, bikinis and hipsters (and I think there were boyshorts as well).
They're SO soft, come in microfiber, and microfiber w/satin, in a TON of cute colors (plus the normal black, white and nude). They're super lowrise with really soft waistbands, so they should be really comfy.
http://www.barelythere.com/landing.asp?cid=2&sid=2&id=7
(and for you GUYS who are wondering "

is she posting about panties?" because we girls are all too familiar with finding panties that don't peek above our riding pants/jeans, and are comfortable for long rides.... Yeah, yeah, I'm spoilin' ya'lls fun, since you LIKE the thong-peek, but

I gotta look out for the girls.

)