Ok, done it. Tell me if I've got it wrong (as if you need the invite).
Norwegian lives on the end (not sure which) and only lives next to a Blue house, so he can't live in White or Green, as they are next to each other. He can't live in Brit's Red house, so
1) Norwegian lives in Yellow house.
2) he smokes Dunhill
If he smokes Dunhill, not Bluemaster, he can't drink beer. And he doesn't drink Tea (the Dane), Coffee (Green house) or Milk (middle house), so
3) he drinks Water.
So 4) Blue house owns Horse (next to Dunhill) and
5) smokes Blend (next to Water). And since he doesn't smoke Bluemaster, he doesn't drink beer. He doesn't drink Coffee, Water or Milk, so
6) he drinks Tea, and
7) he's the Dane.
Pall Mall smoker has birds, so can't be the Swede (who has dogs), can't be the German (who smokes Prince) or the Dane (Blend) or Norwegian (Dunhill), so
8) Brit smokes Pall Mall and
9) Brit rears birds
We have the list of smokers except
10) Swede who must smoke Bluemaster
11) Swede drinks Beer
The Swede can't live in the Green house (coffee), so
12) Swede lives in White house
13) German lives in Green house
The German drinks Coffee, so
14) Brit has to drink Milk
15) Brit red house in centre (order could still be Green, White, Red, Blue, Yellow)
Blue house Blend smoker is next to middle house (Brit with Birds) and Norwegian, so
16) Norwegian has Cats
17) German has fish
That's all nationalities, cigs, drink, colour, pet, but we still don't know the order of the houses. And in fact, it could be:
Green, White, Red, Blue, Yellow
Norwegian lives on the end (not sure which) and only lives next to a Blue house, so he can't live in White or Green, as they are next to each other. He can't live in Brit's Red house, so
1) Norwegian lives in Yellow house.
2) he smokes Dunhill
If he smokes Dunhill, not Bluemaster, he can't drink beer. And he doesn't drink Tea (the Dane), Coffee (Green house) or Milk (middle house), so
3) he drinks Water.
So 4) Blue house owns Horse (next to Dunhill) and
5) smokes Blend (next to Water). And since he doesn't smoke Bluemaster, he doesn't drink beer. He doesn't drink Coffee, Water or Milk, so
6) he drinks Tea, and
7) he's the Dane.
Pall Mall smoker has birds, so can't be the Swede (who has dogs), can't be the German (who smokes Prince) or the Dane (Blend) or Norwegian (Dunhill), so
8) Brit smokes Pall Mall and
9) Brit rears birds
We have the list of smokers except
10) Swede who must smoke Bluemaster
11) Swede drinks Beer
The Swede can't live in the Green house (coffee), so
12) Swede lives in White house
13) German lives in Green house
The German drinks Coffee, so
14) Brit has to drink Milk
15) Brit red house in centre (order could still be Green, White, Red, Blue, Yellow)
Blue house Blend smoker is next to middle house (Brit with Birds) and Norwegian, so
16) Norwegian has Cats
17) German has fish
That's all nationalities, cigs, drink, colour, pet, but we still don't know the order of the houses. And in fact, it could be:
Green, White, Red, Blue, Yellow