I decided against digiKam, as I did not want to create another folder structure for the images I already have. Right now all my Photos are in Windows and I access them by mounting the windows partition as a read only filesystem on Ubuntu. Now when I import the photos through digiKam, it creates a copy of these images and almost uses up my entire space. And the more I think about it, the more difficult its going to be for me to settle on a photo management software. More the pity I guess, as I certainly don't want to boot into Windows every time I modify or add photos.
Meanwhile I found another software called LightZone which is like a RAW reader and modifier. The software looks good, but since I have not yet started shooting in RAW, its most probably going to stay dormant for some time. Hopefully by then I would be able to find a suitable Photo Management Software for Linux.