I really dislike when I hear how "blogs get you noticed". Uh, no they don’t. You get yourself noticed.
What I mean is that if you setup a blog and start publishing stuff on it, it isn’t going to get you noticed unless you do something else. Why? Because you have to make people aware of it first and thus build up a readership or community around it. If no one knows it exists though then how can it get you noticed?
Now here’s my point. The only way to get yourself noticed is to get out there and mingle with people (just like you do in real life). In effect, you are your own best advertisement for your site. Your words on other sites (participating in conversations) is what gets you noticed (as usually people will find it interesting and want to read more). Your content on your site though is what makes these people stick around.
Therefore, if you never step foot "outside" of your home, instead spending time just "talking to yourself", don’t expect to "get noticed".
Update: Actually I just want to emphasize something here. I honestly believe that a person can get noticed without having his own blog. If that person is a part of a community on another blog and comments there frequently, he’ll get noticed there just as much. In other words, it’s not so much the act of having your own blog that gets you noticed but instead committing to a relationship or community where people can get to know you.