Connecting multiple USB devices using a USB hub that connect to the USB port of a Android devices
Typically yes, you can use a USB hub to connect multiple devices without any issues. Whether or not these peripherals perform adequately may depend on the amount of power that they require, but that's common to un-powered USB hubs in any situation.

Google's Android support pages actually mention USB hubs. E.g. the Nexus S support page on keyboards and other devices specifically states:


  To connect more than one USB device at a time, use a powered USB hub to reduce the drain on your phone’s battery.