I just read an article about our search to find life among the stars by trying to listen in on possible broadcasts by interstellar civilizations. Find the article here: http://www.huffingtonpost.com/2013/02/10/seti-alien-life-extraterrestrial_n_2655465.html?utm_hp_ref=science
It's a big universe out there. It takes about 250 million years for the solar system to make a revolution completely around our own galaxy. Our galaxy alone has a few billion stars, and there are a several billion galaxies. It's totally impossible to know how many total stars there may be in the universe and it's certain that there are many more planets to go with those stars.
We may never know if we are alone as advanced technological beings in our own galaxy and certainly in the universe as a whole. There could be many such civilizations, a few or none.
I'm personally convinced that life is ubiquitous in this universe, but I'm less convinced that life easily reaches the heights of development it has reached on this planet. All kinds of things had to line up just right for homo sapiens to come along in recent times and for a very short period of time so far. If that comet or huge asteroid hadn't hit about 65 million years ago, the ecological makeup of this planet would be vastly different, and I seriously doubt any dinosaur was set up to develop the manual deterity or mental capacity to produce a technological world.
Our chimp cousins are very close to us genetically, but they can't speak a language or make fire and they can't make anything more than very simple tools with stuff already complete in their environment. Chimps possess quite a bit of intelligence, but it isn't on a level that is going to give them an internet, a space plane or even a bicycle.
Face it. We are unique and the chances of something akin to us happening in the same way on another planet are close to nil. With so many planets, it still is possible it did, but where and how far away that "where" is would be an entirely different matter.
It's only in the past century or so that we developed to the point where we are broadcasting our presence into the cosmos, and that broadcasting hasn't even reached most possible planetary systems yet. So, if there is a civilization out there looking for a signal from us, they are looking in vain at the present time. We probably are likewise looking in vain. If an intelligent race exists somewhere, it could still be in the pre-stone age stage. We white Europeans wouldn't have been able to detect native americans from as close as Europe if we had mastered radio communication back in the fourteen hundreds because there was no one here doing any broadcasting.
Also, any such intelligent life has to be a terrestrial form. Octopi are very intelligent creatures, but you don't develop fire, metals, technology, etc. in an ocean. If life hadn't crept out onto land many millions of years ago, we wouldn't be here. Crawling into a convenient habitation on the ocean floor may be smart, but it certainly isn't a technology.
Give me or some other homo sapiens an idea or need and adequate tools and materials and we will make whatever we need. I've done it several times in my life and my fellow humans are busily at it every day. We're the only creatures on this planet with that much potential. It took several billion years for us to come along, and I don't think it could be much faster somewhere else and only if the conditions and happenstances were exactly right.
So, we'll keep searching, but I'm not holding my breath for something to turn up any time soon.