Marshall - 1:37 pm on Jul 31, 2012 (gmt 0)
Other variables to consider if using a responsive design versus a mobile friendly one are bandwidth and speed. Responsive designs are nice, but you are forcing a user to download information they may not see or be able to use. You also have to keep in mind that some people pay for bandwidth usage, so why make them download more than they need.
Making a mobile friendly site is not that difficult and personally, I think it is considerate of a website to do so, just as it is considerate to make a site accessibility friendly. Let the user decide what is best to use.