Interesting, tried pinging yahoo.com from my laptop using two methods - connected to a wireless bridge, which is connected via wireless to my router, and wireless using the built in wifi.
Wired to Wireless Bridge (Wireless to Router) -
Ping statistics for 66.94.234.13:
Packets: Sent = 30, Received = 30, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 86ms, Maximum = 147ms, Average = 94ms
Internal Wireless - IBM a/b/g -
Ping statistics for 66.94.234.13:
Packets: Sent = 30, Received = 30, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 87ms, Maximum = 93ms, Average = 88ms