The Hamden YMCA is a great place if you're looking for a cheaper way to entertain your family in the summertime. Not having a pool in my own backyard, visiting the YMCA and using their pool has been a great treat. It's actually one of the only pools that I've found to be WARM!
The pool can sometimes be overrun by seniors doing their laps, but for the most part open swim times are plentiful.
The YMCA also has a bunch of things for kids to do, and they have a lifeguard on staff to watch the pool as well.
They offer trial memberships, and partial memberships and each membership includes full use of their facilities. It's definitely a good inexpensive way to get involved in a good community group.
They also have a summer camp which fills up rather quickly. It's a very popular camp and they do a lot of fun activities and field trips.