Hello,
      sorry for my such dump question... i am a complete to linux. my question is how can i add themes or configure my GNOME or KDE to support themes? For example in the screenshot of following url:

http://www.abbottdavid.com/screenshots/idesk.jpg

there's this weather information and the taskbar is looking different. also in the following screenshot:

http://kencaz.home.comcast.net/linuxscr/lime_theme.jpg

how can i configure my taskbar in such fashion? Sorry my question might be dumb or silly but just want to know how i can make my linux box get such effects. Also can you provide me some links from where i can download such themes etc.

Thanks

themes are desktop environment specific. (ie for KDE or gnome)

try www.kde-look.org and www.gnome-look.org for themes. There is typically a "How to Install" section that will walk you through, or inside the KDE control centre there is a "Look and Feel" section.

The first link is fluxbox i believe, i much prefer that to gnome and KDE, it's less resource heavy, looks better (IMO) and is easy to configure the basics. It's not a full blown environment either, just a window manager that handles the look and feel, so you can use the gnome config tools you are used to alongside it as GDM is running behind it.

Which one YOU choose is down to you, a few basic guidelines though:

1) In most cases KDE uses more resources than gnome, so if you want or need a fairly light system, i'd lean towards gnome or fluxbox (there are others like enlightenment or icewm etc)

2) I find KDE has quite a few small apps that are fun to explore, you dont have to use KDE to run them (likewise with gnome aswell), but installing them means installing a fair chunk of KDE anyway as it comes as a package.

3) KDE's control centre appears to have alot more settable options in it

4) some things in those links you posted are independent, that is to say that the transparent terminal etc are properties of the terminal program itself, it does not matter which environment you run.