Dekka answered really well, but I just thought I'd add some input too!
Tollers should be extremely energetic, active, always on the go dogs. They require
at least an hour of exercise daily, preferably more (both physical and mental). If that doesn't happen, then like many other high energy breeds, they'll find other ways to use up that energy. Ways that result in destruction, non-stop barking, etc. Of course, if they miss one day of full exercise they'll be quite content to lay on the couch and relax but don't expect that two days in a row. They are great at sports such as Agility and Flyball. They're very high drive dogs as well as highly intelligent, quite easy to train dogs (though they can be quite stubborn at times).
They're also very alert dogs. Neither Tango or Dance miss a beat. They can look sound asleep and even if I so much as move my foot they spring up and are ready to go. As far as being independent goes, that very much just depends on the dog. Dance is a velcro dog though.
They should be dog friendly, but there are quite a few that are a bit dog reactive (especially bitches, and especially of they're intact). Many times that has to do with lack of major socialization when they're young, but not always. That brings me to another point. Tollers need loads of socializing all through out their life, and especially as puppies. More so than many other breeds - they're kind of quirky. As far as cats go, many do have a high prey drive but I know quite a few Tollers who live peacefully with cats.
Tollers don't have a "Hi, I just met you and you're my best friend" attitude. Most are pretty reserved with strangers and save most of their exuberance for close friends and family. They're very devoted to their family, and many choose one person inparticular, but not all.
As far as noises go, they're known to be a very vocal breed. They have a wide array of whines, barks, yodels, howls, etc. The Toller
scream (not song) is quite often used when the dog is in anticipation of something, or a state of extreme excitement or anxiety. And no, not all Tollers do scream, but many do.
And here's the "Top 10 reasons not to get a Toller" list:
http://www.calibertollers.com/toller/topten.htm
It's not something to steer you away from the breed, but it's full of information on what a Toller is basically about.