IGN (linked above) has posted its review of the official Sony wireless keypad for the PlayStation 3, and seems to have a problem with its general design more than anything.
They note that the biggest issue is the top mounted nature of it, but essentially QWERTY keypads for game controllers don't really work that well and its probably best to pick up a microphone and talk.
To quote: But regardless of the poor touch support and ill-advised key design, the biggest issue I had with the Wireless Keypad is that Sony opted to design it as a top mounted add-on. I don't want to seem partial one way or another, but I definitely think Microsoft had it right when they made their keypad attachable between the handles of the Xbox 360 remote.
The keys seem much easier to view and access when they are located just below your thumbs on the thumbsticks. To be fair, the choice in top versus bottom attachment may have been out of Sony's hands. It's possible that Microsoft had patented the bottom-mounted design or that Sony simply wanted to distinguish the Wireless Keypad from the Xbox 360 Chatpad.
Whatever the reasoning, the topside orientation of the keypad is, at least in the opinion of this humble critic, a deal breaker. I found that I had to physically tilt the keypad upwards and toward me in order to effectively use the keypad, which was as jarring as it was disruptive.
But the issues facing the Sony Wireless Keypad for PS3 are due only in part to poor design and performance; some blame could also be placed on the product type itself.
When it comes right down to it, QWERTY keypads for game controllers are completely counterintuitive. If gamers want to make quick, concise messages, they are more likely to pick up a microphone and talk than to enter the XMB menu, reach up to their keypad, type out a message, fix the inevitable typos, and then send it.
Even when out of a game, browsing the Internet or otherwise, user are more likely to turn to a USB mouse and keyboard than a compact keypad that seems better suited for the hands of an Oompa Loompa. More PlayStation 3 News...