Tuesday afternoon . . .

. . . in North America.  Wednesday in some other parts of the 
world.  In any case, last chance until 2117:

http://apod.nasa.gov/apod/ap120603.html

For a rough observing guide, including precautions to take when 
observing the Sun any time:

http://www.skyandtelescope.com/observing/home/Transit-of-Venus-February-2012-134332798.html

Basically, first contact occurs right after 6pm EDT, 5pm CDT, 4pm 
MDT, 3pm PDT, so you want to be in place with your equipment if any 
ready before that time.  For more information, check out the links in 
and below that article and those shown on the right-hand side of the 
page.  (Some may be duplicates of others.)

Detailed times and such available here:

http://xjubier.free.fr/en/site_pages/VenusTransitCalculator.html

though it seems to be busy and taking awhile to load today.  Keep trying.

If it's cloudy where you are, one place to watch the event live on-line is:

http://venustransit.nasa.gov/transitofvenus/

Other links here:

http://www.skyandtelescope.com/observing/highlights/Where-to-See-the-Transit-of-Venus-Online-154213475.html

though if previous events are any guide, many of the live sites will 
probably experience a lot of traffic during the transit and may be 
slow, drop connections, etc., so, again, keep trying.

Also, by coincidence, there's a partial eclipse of the moon tomorrow 
morning, beginning almost exactly 36 hours before the transit begins 
(i.e., 6:00 a.m. EDT, 5:00 CDT, 4:00 MDT, and 3:00 PDT).  Again, the 
further west you are in North America, the more you will see.  More 
at 
http://www.skyandtelescope.com/observing/highlights/Partial-Eclipse-of-the-Moon-ar-Dawn-June-4th-143680466.html.




. . . ronn!  :)