Having text link navigation at the bottom of your pages allows you to target the specific keyword in the anchor text and send valuable PR juice to the pages you want and nofollow all others. Which means you will have better control over the terms used in anchor text as well as where your PR will go. Remember having the text link in the body text will give you the most “juiceâ€, but if you can’t force it, the bottom of the page is better than nothing. Also, remember of the recent bug in Google – if you have an image link, you have to have a text link too somewhere on the page.
Do you mean a text navigation both on top and bottom or just one on the bottom? If just one on the bottom, why? I would get annoyed to scroll down just to navigate, very user unfriendly. Also, you can easily target every keyword no matter where your text navigation is.
mm thanks for the info. even i am worried about the issue "image linking" that is why i preferred to have a anchor text (text link) rather than image links.