I want to make my usb drive as live cd, so I can bring my live cd in my usb. Is it possible to copy the iso file to usb so I can use the usb as live cd? and if it is possible, how to make bootable usb from my iso file?

Yes, We think it is possible to make live cd in your usb. You can use LiLi USB Creator to make bootable usb. This software is too simple to use. You just need to download the software from this website: http://www.linuxliveusb.com/, then follow five simple steps. Each steps (except step 4 and 5) has traffic light for the indicator if the step is managed successfully.

First step is choosing the usb drive, then the second step is choosing the source. You can choose the iso / img file, CD or download the file. The third step are managing the persistence. The fourth step is choosing the options such as Hide created files on key; Format the key in FAT32 (this will erase your data!!); and Enable launching LinuxLive in Windows (requires internet to install).For the final step is clicking the lightning icon to start the installation.