Warning*  This one takes some patience to setup.

 Nimbuzz Lite allows you to use aim, yahoo, msn and other instant messenger programs on your boost mobile phone. 

 This program is really laggy on my i335 and I can't seem to get past the login screen.  So you may experience the same issues.

1:  Go here and download nimbuzz lite click here.

2:  Go to this site and follow the directions. click here

3:  Go to nimbuzz.com and sign up for an account if you don't already have one. 

When going through the installation process this program had a few bugs. Such as having to hit the OK button several times, long waiting periods, etc..  Some people have had no issues while others still can not get it to work 100%.  

Let me know if you have been able to get it to work or not.