JQuery :: Find Out If An Element Is A Drop Down List?

i have a couple of elements on my web page, that i want to manipulate in one loop.

jQuery.each($(".specificClass"), function(i) {
// do something
}

Within that loop i have to check what type of element that very one is e.g. a <div> or a <span> or an <img> or a <input type="button"> or something else.I managed to isolate some of them, the easiest was the button where i checked the following:

if ($("selector").is(":button")) {
// do something
}

In the jQuery API 1.3.2 there are some more useful Forms Filters like :input, :text, :checkbox etc. What i really miss is something for a drop down list. I would have expected that there is something like

if ($("selector").is(":select")) {
// do something
}

but i could not find it.It would also be great to have something to check if the element is an image. I have read that there exist such a check, but that is for images that are input-images within a form. I am longing for a simple check for an image somewhere in the web page.

if ( !isNullOrEmpty($("selector").attr("src"))) { // --- image ---
// do something
}

[code]...