You could use Sharepoint Team Services Discussion Threads and embed it in a
Web Parts.

This is what I used for my company and it works great

If you need more info, feel free to let me know

Could you please specify in detail ,how do we go about doing this

I too am interested in this, please elaborate.

Here is an easy way to do it

Team Service Site
1. In a Team Service site, create a new Discussion Board
2. Customize to match your need
3. Locate the view you want to publish in Portal Server for instance
http://server/Lists/General%20Discussion/Expanded.htm
<http://server/Lists/General%20Discussion/Expanded.htm>
4. Edit this view with FrontPage 2002, and delete all the content you don't
want to show, like top toolbar and side navbar
5. Edit all the other dependant pages to remove extra navigation like
http://server/Lists/General%20Discussion/NewForm.htm
<http://server/Lists/General%20Discussion/NewForm.htm>
6. Make sure users permissions is set for the team site

Portal Server
1. Create a new web  part with HTML content
2. In the link properties, paste
http://server/Lists/General%20Discussion/Expanded.htm
<http://server/Lists/General%20Discussion/Expanded.htm>
3. Click isolate content
4. Adjust height and width

You're done. We did this successfully for publishing Calendar, list and
other valuable information

They might be more fancy way to do it using VB Script and CAML that will
give you more control but this works pretty well.

But only problem is i only have
Sharepoint Portal Server and no Sharepoint Team Services. Does anyone
know where we can download this web  part from?

This web  part assume you have Sharepoint Team Services. If you don't it is
included in Frontpage 2002 and has no licensing requirements other than a
vlid license of Frontpage XP or Office XP