Bootmii

I'm not sure where to post this but is it anyway to use a usb to back up your nand, cause i don't have a big enough sd card and I'm am no where near somewhere i can get one nd i i got no money to buy one big enough so is there anyway we coulduse a usb too.

No, there is not as of now.

USB is not currently supported in MINI (i.e. BootMii). Therefore, it is not possible to backup NAND through BootMii to USB. You can dump NAND to USB through other apps, but you will not be able to restore that dump through BootMii in case of a brick. I advise you get a bigger SD card, you can get them quite cheap nowadays. I'd go for either a 1GB or 2GB.

No, USB is not supported in BootMii.