$('div:hidden') gets all 'div' elements which have their 'display' style attribute set to 'hidden'
$('li:eq(0)') gets the first item in the list
$('li:lt(3)') gets the first 3 items in the list (0 based)
$('li:even') gets all list items with a even index (0 based)
$('li:not(.some)') gets the lost items which do not have the css class ‘some’
$('p, li.some') gets all 'p' elements as well as all 'li' elements with a css class of 'some'
$('li .some> p') gets all 'p' elements which are children of any element with a css class of 'some' which are in turn children of a 'li' element
$('p a[@href*=http]') gets all ‘a’ elements which are children of a ‘p’ element that have a ‘http’ within the ‘href’ attribute
$('li + li > a[@href$=zip]') gets all 'a' elements which have 'zip' in the 'href' attribute which are children of a 'li' element which is in turn the child of another 'li' element