WordPress.org

Can I use more than one instance of this widget?

Yes, Twitter Widget Pro employs the multi-widget pattern, which allows you to not only have more than one instance of this widget on your site, but even allows more than one instance of this widget in a single sidebar.

Can I follow more than one feed?

Absolutely, each instance of the widget can have different settings and track different feeds.

Why can't I display a friends feed anymore?

Aparently the database queries required to display the friends feed was causing twitter to crash, so they removed it. Unfortunately, this is outside my control.

I get an error similar to "Parse error: syntax error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or '}' in /.../wp-twitter-widget.php on line ##" when I try to activate the plugin. Is your plugin broke?

No. This error occurs because the plugin requires PHP 5 and you're running PHP 4. Most hosts offer PHP5 but sometimes you have to enable it in your control panel, through .htaccess, or by asking them. There may be instructions for your specific host in the Switching to PHP5 article in the codex.