Adapted from http://superjezmeralda.tumblr.com/post/98656691396/stereotastic-to-tumblr-bookmarklet

Stereotastic Bookmarklet.js

javascript:
if (location.href.indexOf('stereotastic.com/') > -1 ) {
    var re = /\/[A-Za-z0-9]{6}$/;
    var m = re.exec(location.href);
    if (m[0] != null) {
        var wiggle_url = 'http://stereotastic.com/img/user'+m[0]+'.gif';
        var tumblr_share_url =
            "http://www.tumblr.com/share/photo?source="+encodeURIComponent(wiggle_url)
            + "&caption=" + encodeURIComponent('<p><a href="'+location.href+'">Stereotastic</a></p>')
            + "&click_thru=" + encodeURIComponent(location.href)
            + "&tags=" + encodeURIComponent('3DS, Wigglepic');
        window.open(tumblr_share_url,'_blank');
        void(0);
    } else {
        alert('No URL match.');
    }
} else {
    alert('Not on Stereotastic.');
}
void(0);