This is what wikipedia has to say about them;
Brushtailed possums are also very intelligent creatures, with brainpower comparable to a dog. This makes hand reared possums ideal to teach tricks. Common tricks can include "sit" and "hiss" but they can also be trained to "fetch" with enough time. It is important to remember when training brushtailed possums to be firm with the instruction and always give a reward such as fruit or vegetables.
This is interesting as Tim and Mandy use apples to give me during agility training, so I don't see why they shouldn't come along. Their brainpower is comparable to mine (although I have never read a possum's blog.) I reckon they might do all right if we take them along tomorrow.
Life is great when you have lots of furry friends.