jQuery JSON call best practice

gistfile1.js

$("#show_teams").live("pagebeforeshow",
                            function(event,ui)
                            	 {
	                             $.ajax({"url":'http://hockey-community.com/api/users/<%= @current_user.username %>/teams',"dataType":"json","async": false,"context":this,
	                                    "error":onError(), "success": function(teams)
	                                    		{
												console.log("calling API for teams");
												if (teams.length > 0){
			                                   		 $.each(teams, function() {
																console.log('loading team'+this.team.name);
																 $("#teams_listing").append('<div><a href="'+this.team.link+'" class="ui-link"><img alt="'+this.team.name+'" height="65" src="'+this.team.profile_picture+'" width="65"></a><span>'+this.team.name+'</span></div>');
																});
													}
												else {
													$('#teams_listing').html("<p>You're not in a team for now but you can join or create one on our website.</p><br>Please visit http://hockey-community.com from your computer.");
												}

												$('#show_teams').page('refresh');
			                                    }
	                                    });
	                             });

Why do you say "async": false ?
I use the default value (true)
read Jquery doc :
"By default, all requests are sent asynchronously (i.e. this is set to true by default). If you need synchronous requests, set this option to false. Cross-domain requests and dataType: "jsonp" requests do not support synchronous operation. Note that synchronous requests may temporarily lock the browser, disabling any actions while the request is active."