This is pretty cool and acceptable for either girl or boy: http://www.landofnod.com/family.aspx?c=3500&f=4384&pc=5
I spent months fretting over baby bumpers only to find out that my daughter liked to smash her face against them. The custom made (by my mother) bumpers were on her crib for about 30 days and have remained in the closet for the last eight months. When she started moving around more I had to invest in breathable bumpers because her arms/legs would get stuck between the slats and she would get scared.
http://www.amazon.com/Breathable-Baby-10111-Bumper-White/dp/B0013FGWD0/ref=pd_bbs_sr_1?ie=UTF8&s=baby-products&qid=1207624953&sr=8-1
If I had it to do again I would buy the breathable bumpers from day one and get some cool sheets to add punch to the room.
Good luck!