Tosh's answer has the filter idea exactly right. I recommend do it just like that. However, if you do this, you should use "ng-href" rather than "href", since following the "href" before the binding resolves can result in a bad link.
filter:
'use strict';
angular.module('myapp.filters.urlEncode', [])
/*
* Filter for encoding strings for use in URL query strings
*/
.filter('urlEncode', [function() {
return window.encodeURIComponent;
}]);