I use the XBOX360 so I'm not as sure about the PS3....but it will vary by game and by opposing player...many if not every online game has a "ping rate" readout, usually in the "game lobby" or at times in the scoreboard section, you will usually be able to read a "Ping Rate" for each player, that makes it hard to do "direct" comparisons (wired vs. wireless) to the same endpoint (player or server)
http://boardsus.playstation.com/t5/Warhawk-PS3/Whats-your-Ping-rate-and-how-do-I-improve-it/m-p/31503815http://www.techsupportforum.com/gaming-forum/console-gaming-support/204641-ps3-cod4-lag-killing-me.html