My Samsung Galaxy S doesn't recognize when it is plugged in to USB When I plug in my Samsung Galaxy S (Model SAMSUNG-SGH-I897, Firmware 2.2, Kernel 2.6.32.9, Build FROYO.UCKB2) to a computer, it starts charging, but does not recognize the USB connection for data.  I have tried toggling debugging, mass storage, and ask on connection, but all that happens is that it draws power.  I've tried both Windows 7 32bit and Ubuntu 11.04 32bit.  It was working yesterday.

Additional note: dmesg, lsusb, and adb do not recognize the device at all under ubuntu

Thanks
This has happened many times to me, and every time it has been a bad cable. If you have one, try finding another USB cable to test it with, and see if it works. Often some connection goes bad in the cable just from use and wear and it will only charge and refuses to transmit data. 

The other possibility (this is known to be a problem with the EVO 4Gs, but i don't think i've heard of it on the Galaxy S) is that the USB port on your phone has been damaged or gone bad. This happened to my dad's phone (EVO) and they sent him a replacement.

Let us know what happens after you try a new cable!