Blatantly copied from the macforums for tweaking safari to use "iphone" user agents: "to make the develop menu show up, you have to go to: preferences>advance

Blatantly copied from the macforums for tweaking safari to use "iphone" user agents: "to make the develop menu show up, you have to go to: preferences>advanced tab>check "Show develop menu in toolbar" then go to Develop>User Agent>Mobile Safari iphone 1.1.3"