Link Exchange can be useful for increase site PR and back link or not ?

Hi Everybody,
I mostly heard about link exchange but I never used it. I want to know that it can be useful for increase my site PR and Back link or not ? I also want to know that google give weight to those links which we got by link exchange program or not ?

Thanks in advance for your suggestions!

Yes link exchange is grow you website pr if you have good pr and quality link exchange.
A link exchange is a confederation of websites that operates similarly to a web ring. Webmasters register their web sites with a central organization, that runs the exchange, and in turn receive from the exchange HTML code which they insert into their web pages. In contrast to a web ring, where the HTML code simply comprises simple circular ring navigation hyperlinks, in a link exchange the HTML code causes the display of banner advertisements, for the sites of other members of the exchange, on the member web sites, and webmasters have to create such banner advertisements for their own web sites.

I flat out refuse link exchanges nowadays and recommend the same to people who ask me to swap links. It’s a dated process. Yes perhaps for a brand new site a few link exchanges with theme-related sites will get you going, but I believe it’s a waste of energy. Spend your time forming relationships and writing content instead.