an array of strings as a jQuery selector?
Try the Array.join method:
var a = ["#p1", "#p2", "#p3", "#p4", "#p5"];
var s = a.join(", ");
//s should now be "#p1, #p2, #p3, ..."
$(s).whateverYouWant();
Well, there's 'join':
["#p1", "#p2", "#p3", "#p4", "#p5"].join(", ")
EDIT - Extra info:
It is possible to select an array of elements, problem is here you don't have the elements yet, just the selector strings. Any way you slice it you're gonna have to execute a search like .getElementById or use an actual jQuery select.
What about $(foo.join(", "))
?