A little more JavaScripting.. If you go to vimeo. e.g. like this:

http://vimeo.com/18047390

you might recognize that the video is quite small and you cannot do something about it (besides fullscreen, and waiting 3,5h for the flash-Esc-fullscreen message to disappear). Now you can!

• install greasemonkey (oh! .. ehmm for Firefox of course! But Chrome can handle userscripts by default? Says mychromeaddons.com. At the installing-page of userscripts.org is nothing about that yet however…)
• install my little script: vimeo bigger video
• resizes only on video page
• resizes video scroller on the right too
• removes flash scrollbar, reactivates standard one (flash-Thing was bugging me)
• voilà:

btw: userscripts.org is a little slow these days. Here is a backup: vimeo_bigger_video.user.js