I wish to know how i can protect my comp from the poison websites.
Heard of some java script or other malwares and scripts that get activated just by visiting the websites.
How can i protect my comp / browser from them ? and
How can I detect if my browser is already compromised or not.
Plz advise.

If you use firefox, you can use add-ons like NoScript and Flashblock.

as a perfect solution: don't use java and flash at all. that will solve more problems. not all, of course.
if you run firefox, you can also change your user-agent to avoid some attacks at firefox, made by checking user-agent.

So you mean no more Java, no more flash, no more java script (or any other script)
But these days there are many websites which are 100% flash based. There are many financial web sites that work totally on Java. So how do we be sure we are safe ?
How can i change my user agent and what should i change it to ?
Moreover, is there any way to know that my browser (firefox) is in perfect health

NoScript will let you specify which sites and/or addresses are allowed to execute Java, JavaScript, Flash, etc. in your browser. If you wish to have protection even from trusted sites, one option would be to use a virtual machine for your browsing needs.

Search here and you'll find add-ons that do this for you. You can change it to whatever you like, but keep in mind that this technique would be security through obscurity so you would be foolish to rely on it for any serious protection.

One way would be to use a HIDS (which can actually tell you about your entire system's health). That said, one cheap yet effective way to reduce the risk posed by malicious code on the Web is to use disposable accounts for certain things. Personally, I use the guest account on my Ubuntu box quite a bit. It self-destructs after every use.

type in about:config in your addressbar.

search for useragent

change firefox to something else

An especially paranoid approach could involve cruising the web from a live CD.

So it seems from the replies till now that Linux browsers are equally vulnerable as Windoz, because :
(1) its the same browser on a different OS,
(2) the security is dependent on users decision to visit a site or not,
(3) security is dependent on how much i avoid using the features (scrips flash etc) and not on protection available in Linux.

I would be happy if i am wrong but plz correct me.

I am a very ordinary Linux user, not a geek, for me making decision b4 visit EVERY website for getting information is very difficult. Already there are many websites of important companies and financial establishments who offer a IE specific website, on top of that if i close down all other things like scripts and flash then i cut down the size of 'available' internet for me. Its something like living in China where a large section of internet is not available to ppl.

Moreover there seems to be no easy way to detect that my browser is infected.

An "infected" browser is much less likely on Linux than it is on windows. Make sure your browser and plugins are updated, i.e. Adobe Flash, Sun java etc.

if you use Firefox;
Use NoScript and only allow sites that you can more or less trust to run scripts.
Use AdBlock+ to block other crud.

If you want you can use a hosts file to block a lot of the known "bad" sites. I have used the one from http://www.mvps.org/winhelp2002/hosts.htm on my wife's windows system and on my linux system for a couple of years.

Most of all never ever run a web browser as root.

My system is a bit over 5 yrs old, I have used Firefox with the same profile all this time, not once in all this time has my system or my browser been compromised.

There is such a thing as being too paranoid.

But in many distros like PUPPY (and there are several others) the browser is always run as root.
So in that case using Puppy is a very risky thing to do. Is it so ?

Same-brand browsers can contain significant differences between their platform-specific versions. That said, I would agree that the vulnerability could be about the same, generally speaking. You'd need to conduct a formal assessment to get an accurate picture, though (otherwise assuming the worst would be a healthy practice). On the other hand, the overall risk represented by GNU/Linux browsers should indeed be lower (due in part to the much lower threat level). And yes, it's completely normal for security to involve a compromise of usability/features (this is true on any operating system).

Yes, the more privileges your browser runs with, the more damage can be caused by someone who exploits it.

Well you scare me I like Puppy and often use it for small work esp while traveling. So you say Puppy and Slax or similar distros are relatively unsafe

Can you suggest any other distro similar to Puppy which does not runs as root ?

I can see how one could draw that conclusion from my statement, but I was actually referring exclusively to the browser issue. I can't speak of either of those distros, since I don't use them. Besides, surely they let you set things up the way you want, right? Or are you obligated to run your browser as root? Can't you create a non-root account and use that instead?

No, but maybe someone else can.