The lightIRC project just released version 0.9.8 of their free Flash webchat which contains a bunch of bugfixes and feature additions.
lightIRC Webinterface
The biggest improvement probably is that the client now offers “basic SSL support” which is still marked being beta at this point.
A whole host of new parameters for better customization has been added – you now can predefine the ident, realname and quitmessage the client uses. Also a new translation has been added, lightIRC now speaks Polish 
A detailed changelog as well as the download can be found here.