The webcam in the Thinkpad Z61t is a Sonix sn9c201+OV7660 and it is supported by the gspca module in Kernel 2.6.28. (I didnt tested that myself because I have no Z61t but I saw the sn9c* stuff in the Kernel.
The webcam in the Thinkpad X301 (and i guess in all other Thinkpads in this generation) is supported by uvcvideo. It is a USB standard for Webcams (pretty cool actually. I didn't know something like this existed) You can take videos (see yourself) with mplayer by using the video4linux 2 driver. The call would look like this.
mplayer driver=v4l2:width=640:height=480:outfmt=i420 -vo xv tv://
Note that one taking videos you cant go above 640x480. Anyway the quality is pretty good. Even the green led next to the webcam is on.
You can take pictures with uvccapture. The call would look something like that:
uvccapture -x1280 -y1024 -o002.jpg
Note that in this case (for a single picture you can go to the maximus resultion of 1280x1024px
Maybe someone can write a newbie guide on how to find and enable the uvcvideo module (I think it's somewhere in Device-Drivers->Multimedia Devices->V4L->USB capture devices)