Linksutra

If you already have your own joomla component then it is fine otherwise create new one for yourself within minute.  Joomla Component Creator
Lets assume we have component “ajaxcall” and we are making ajaxcall from “com_ajaxcall\views\ajaxcall\tmpl\default.php” file.
We will make ajax call  to the format “ajaxcallformat” (i.e. view.ajaxcallformat.php)
javascript code in “com_ajaxcall\views\ajaxcall\tmpl\default.php”

<script type="text/javascript">

function AjaxCall(name)
{

var httpxml;
try
{
// Firefox, Opera 8.0+, [...]

Linksutra Profile Module (needs Linksutra Profile Component)
Linksutra Profile Component
These component and module provides facility to joomla admin to create social networking site easily.
UPDATES:
1) backend admin part to customize profile and translations (no 404 error anymore) .
2) phpthumb support for thumbnail in profile,scraps,friends etc
3) live updates from friend stream on profile
DEMO Download
Features:

1) Users Profile
2) [...]

Linksutra Profile Module (needs Linksutra Profile Component)
Linksutra Profile Component
These component and module provides facility to joomla admin to create social networking site easily.

DEMO
Features:

1) Users Profile
showing the total visits, friends connection, friends, 5 demands and offers of user , basic information of user like about me, city, age, gender etc
2) friends:
showing the list of friends [...]

I will try to explain how you can use wordpress MU (2.8.4)  inside your joomla (1.5)  to create blogs for your joomla users automatically.
you will not want  every joomla user to have blogs without actually user wants it to create.
keeping it in mind we follow these things.
1)  install wordpress MU inside your joomla main installation [...]