Typical and nice Tazanian souvenirs to me are the ebony wood carvings from the Makonde tribe, in the southeastern part, though they sell these carvings also in the bigger cities elsewhere in the country. If you are lucky you meet an artist and you can ask him to make a specific figure, which will take a few days (so I heard).
Tanzania is a bit less developed than Kenya and to my experience the people in Tanzania are a bit less polite in the way of asking for money. But I've been in Kenya only for a few days in Mombasa so I don't have much to compare(stayed in Tanzania for 3 months).
As for the game, Tanzania also has the very large Selous park, which I love because it was my first real safari. It is much more quiet than the parks in the north so you dont see many tourists but the animals are also less used to cars, which make them to run away earlier. I think this is the charm of Selous and the real wildlife. There is a big lake in the park, where we made a boat safari, with many crocodiles bathing in the sun and suddenly running from the bushes in the water because they were afraid of the boat. And many hippo's, which you dont want to approach too close..
And we went to Selous by train, from Dar es Salaam, which is a wonderful experience! You meet the local people, talk to them, and in the end you drive trough the park which gives the opportunity to see some animals already. We went back to Dar with a small 8-person airplane with a beautiful view down at the landscape of rivers, forest elephant herds, etc. Very, very nice :)

And for the tsetse flies: I mainly experienced them in Selous. Wear long sleeves and trousers. Mosquito-repellent stuff does not work for tsetse flies

Appreciate your response, Lucky-Me! Sounds like you have had, and are continuing to have, some memorable African experiences!

Aren't trains wonderful? My first trip to Kenya many years ago included an overnight train ride from Nairobi to Mombasa--an experience I'll never forget. I think I read recently that this is something one can no longer do? But a train ride in Tanzania sounds like an awesome experience!

Happy travels to you! I leave tonight for my first leg of the LONG journey----5 hrs from HNL to LAX, then another 19 hrs to Africa. Needless to say, getting pretty excited!!!