[Plugin: WP jQuery Lightbox] lightbox and featured images

hi i’m working on a portfolio site and i’ve got a main menu which displays a set of featured image thumbnails that i’d like to link directly to the lightbox. is there a way to wrap the_post_thumbnail() with a link tag? i’ve tried this(amongst other things):

<a rel="lightbox[post id]>the_post_thumbnail(size)</a>

i probably need to use something as an href but i do not want to go to a new page. i’m probably just overlooking something but i’m also fairly new at coding. can you help?

http://wordpress.org/extend/plugins/wp-jquery-lightbox/