I just posted the following at the ufaq.org forums:
http://ufaq.org/modules.php?name=Forums ... pic&t=2535
no choice in internet search from the address bar in 7.2?
....AOL/Netscape shouldn't have limited users to Netscape search in Netscape 7.2. I hope they address this issue but, in the meantime, more advanced users can try copying over the searchplugins folder contents from another version of Netscape or Mozilla.
Another option, probably easier, would be to download and install additional searchplugins from http://mycroft.mozdev.org/
All you need to do is to click on the name of a searchplugin, and you will be asked if it is OK to install:
Click OK, and that's it!
For example, in the "Browse the categories" General category I installed the following, which then appeared in the Internet Search preferences AND in the Sidebar Search dropdown list: