Um, ok!
I've never seen any proof that life exists on any other planet.
Since the human body cannot function at 0g for long enough to sustain a distant space voyage, we may never know.
With that being said, Humans are the most superior, and intelligent species on all of Earth, and if our bodies cannot handle it, I don't think that IF there were any other life forms out there, they would be able to travel to us either.
Additionally, Earth has a TON of space debris in the inner Earth orbit, which can easily been seen by any astronomer. If there were other forms of life, I would assume we'd be able to see their space debris too.
Also, the chances of any inhabitable planet existing other than Earth is astronomically small (pardon the pun!). There are BILLIONS of factors that make the Earth inhabitable, (self-supporting eco-system, consistent temperature, a non-harmful atmosphere, to name just a couple).
Sure, there have been planets found with the same exact atmosphere, and nitrogen-oxygen mixture as Earth, but that one planet has no land, it's purely made of water, down to the core of the planet which is Ice. There's also another planet very similar to Earth's land-water make-up, but it is on an elliptical orbit, making the temperature have a VERY wide range, and only livable for 2 or 3 thirds of it's year.
So NO, I don't think there are other life forms out there, because I have not seen one simple piece of evidence to support that claim!
(That better jhall?
)