>My PC has two USB ports. Both are already taken. Now, I have this camera which I can use a USB cable to also use it as a transfer medium. However, I don't have any more spots to plug it. Are there Y connector for USB? If not, is there any other alternatives other than to unplug one to plug that one temporary?

You can get a USB hub
http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&affid=&dept=0&WLBS=004P1C2A&mscsid=MFWUC6NMGTMG9KJ1XGVLQQ6XLNMAEAAD&sku_id=06650000000040266&catid=10272&newdeptid=1

Another thing you can do is buy a USB device such as a Microsoft Natural keyboard (which I have). You plug it into your PC USB port, then you can chain (plug in) two USB devices to the keyboard. If you always buy USB devices that themselves have USB ports on them, you will never run out of USB ports.
http://www.microsoft.com/products/hardware/keyboard/natkeypro.htm

Are you sure your two existing USB devices don't have ports on them for chaining?