The average user may not be able to view it, but it doesn't take a pro to intercept your password either. A little packet sniffer will give then the info they need...full access to your account.
Now, the level of risk depends on a couple of things. First, are you using a n unsecured wireless connection, such as a public hotspot? If so, you are quite vulnerable, as anyone could be 'listening in.'
Also, it depends on what it is you are securing. The password to your free e-mail service you may care less about, but if your bank isn't using a secure connection then you should switch to another bank, or at least avoid using their online services.
To protect yourself, always make sure the site you're accessing is legitimate and that they are using a secure connection. In Internet Explorer, you should see a lock at the bottom in the status bar. In Firefox, you'd see it in the address bar in the right corner. The URL would also usually start with https:// instead of the standard http://. Also, keep your AV and anti-spyware software up to date and run it often...that will prevent someone from installing software on your computer to record our keystrokes. (See Keylogger.)
Hope this helps,
P.S. A lot of sites will use a secure login page so that your password is protected, but then the following pages will be unsecured. Depending on what data is protected by the password, that may be indifferent or bad. However, that is why you'd receive an alert about switching to an unsecure page immediately after submitting your login criteria.
When i try to log on to some acount of mine, internet explorer warns me by telling me that, information sent on the network in clear text, will be readable by everybody else. My question is, how easy is it to get these information and if you need som special software to do that? Is there some way to prohibit that?