why thera are css/javascript errors on google?
(javascript: see gmail :p)
css: fe:

.ch{cursor:pointer;cursor:hand}

double decleration? or just a mistake on my part?

CSS errors like these are quite frequent and may be known and wanted to achieve certain effects. For example, while the property "hand" is incorrect according to the W3C, I vaguely remember a certain browser needing it and not understanding pointer. Thus, this piece may mean "take 'pointer', or if you don't get a hiccup with 'hand', take 'hand'".

Other than the false property double declarations are legal, tho usually you'll see them in combination with the!important keyword. Example:

padding: 10px!important; /* Firefox and others */
padding: 20px; /* IE6 */