Two datapoints :
Jan 2006, full bicycle, tightly packed, 100 pounds to ship to USA by surface mail. It's insane to ship by any other method. Don't assume that airmail or less time in the mails reduces the chance of damage, I have never seen evidence of this.
July 2006, frameset only, packed in bubble wrap, 45 pounds to ship to USA by airmail.
- Don Gillies
San Diego, CA, USA