The container is a round Altoids tin covered in camo duct tape. Trade items are not required; if you bring one, it should be small.
Pulaski Park is right in downtown Northampton and is a frequent gathering place for musicians, skateboarders, and families with kids. Watch out for foot traffic and try to be unobtrusive grabbing the cache.
The cache is public-transit friendly! Students can get here using PVTA routes 39 or 39b (from Mt. Holyoke and Hampshire,) or M40 or B43. (That last link is a PDF.)
A monument at the head of the park explains how it was named for Casimir Pulaski, a Polish citizen who took the colonists' side in the American War of Independence, by the large Polish population of the area.
The significant architectural feature of Pulaski Park is the Academy of Music Theater, one of the first municipally owned theaters in the country.
This cache is not snow-accessible.
Note, September 14, 2004: I'm told the pencil in the cache is unusable, so bring your own writing implement to sign the log (you've got one in your bag, right?) until I've had a chance to replace the pencil. (It's a micro, so I need to make a custom pencil...)