If you need a USB speakerphone that's compatible with Microsoft Lync (or Microsoft Office Communicator), it's hard to beat the Polycom CX100 for durability and quality.
In my real job, I rely on Microsoft Lync, not only for attending conference calls and messaging with colleagues, but also for my office phone. I don't have a regular desk phone. All of my phone calls go through Lync, so I need either a headset or a speakerphone for my computer. After a lot of research, I decided on the Polycom CX100, and I'm very happy with the choice.
The CX100 is small and conveniently portable. It comes in a neoprene zippered case, and when you're not using it, the cord stows away nicely in a compartment on the rear of the speakerphone. The cord is relatively short (about 4 feet), and while I'd like to have a longer cord, it hasn't been a real problem. I am a little bit concerned about the thinness of the cord because when you store it, you wrap it around a spindle on the back of the device. It seems that over time, this may lead to a possible short in the cable. However, I've owned the device for several months, and despite winding and unwinding the cord on a daily basis, I've experienced no problems at all.
The CX100 plugs into any USB port on your computer. (It doesn't require a powered port.) When you receive a call, the ring plays through the speaker on the CX100. There are hard buttons on the device for answering and hanging up calls, for volume, and for muting the microphone. When the microphone is unmuted, the lighted ring around the buttons illuminates in green. When the microphone is muted, it changes to a red light. I like this feature a lot because knowing at a glance when your microphone is muted is important.
Sound quality on the CX100 is clear and undistorted. I do rarely find that the volume isn't quite as loud as I'd like, but it's loud enough. The microphones are high quality and I've never had any issues with anyone hearing me, even when I'm several feet away from the device. Perhaps the best feature of the CX100 is that it doesn't require a battery, so if I'm stuck on an all-day conference call, I don't have to worry about losing my hands-free phone.
By the way, I have tried using the CX100 with an iPad using Apple's camera connector kit. Unfortunately, it doesn't work with an iPad. That wasn't really suprising to me since most devices don't seem to have enough power from the camera connector kit's USB adapter.
If you need a high-quality speakerphone for your computer, you can't go wrong in choosing the Polycom CX100. It's made by the same folks who make high-quality speakerphones in use by many businesses, and it's convenient, durable, and portable.