Zpeech has a few advantages over Yaplet. First, it's easier to initiate a Zpeech chat on a site. You just type the Zpeech.com URL, a slash, and the target domain. For example: www.zpeech.com/webware.com. Yaplet can also be kicked off by a URL, but the syntax is not as simple. Zpeech is also prettier than Yaplet. The chat window pops up over your page and can be moved around easily. A Yaplet chat can also be opened in a separate window, but when I tried, it opened up a whole new browser tab. Finally, Zpeech conversations are persistent, like message board postings. Yaplet conversations are like IM chats, and there's no record of historical conversations.
But we have three issues with Zpeech. It requires registration before you can chat. That will keep the trolls away and the noise level down in a room, but we think it will also keep casual conversations from starting at all. Second, Yaplet allows you to move from a public chat to a private online conversation with anyone who's in the room. Zpeech chats are all public. Third, Zpeech limits you to making two comments per minute. So much for rapid-fire chats.
As an ad hoc site-based message board (as opposed to chat) Zpeech works fine, and that's what its builders created it for. It's flow-control features and registration requirement keep things sober. That's why we like Yaplet so much more.