Lets look at a picture (Look for the numbers, if you're clever, you'll notice they the connection between the numbers in the picture, and the list below).

1. No wang = not male. Actually, maybe they're wearing clothes.
2. Wait a minute... they don't have boobs either = not female. Well... not adult female anyway.
3. Hobbit-hole... this is just subtle promotion of the works of JRR Tolkien, engineered to cleverly to create a larger viewing audience for the (then) upcoming Tolkien films. Sneaky, but not gay.
4. Windmills! These things create energy in a frighteningly clean way. Possibly gay...
5. Handbag. Quite frankly, rather than showing the Teletubbies to be flaming queers, I think it probably means the Teletubbies are intergalactic children, and the purple one happens to be a girl. Think about it. They talk and act like they're three-years-old, and their physical proportions indicate pre-pubescence. Children have always loved to imitate their parents - clearly this little purple girl is carrying a handbag because her mum does.
The Teletubbies DO NOT promote homosexuality. Don't be so god-damn stupid. You want to see what promoting homosexuality would look like? Here you go.

The Teletubbies don't promote homosexuality. You can't 'promote' homosexuality. You can promote cool, refreshing Coca-Cola, but homosexuality is something you are or you're not. People piss me off.
Cheers,
Pip