Code:
mount -t auto /dev/sda /mnt/sda
works.

In fact, the system showed me a small trick. Before I upgraded it, the device for the USB stick was /dev/sda; for some unknown reason (maybe I pluged in my friend's on the other USB port), dmesg says:

Code:
scsi1 : SCSI emulation for USB Mass Storage devices
  Vendor: USB 2.0   Model: Mobile Disk       Rev:
  Type:   Direct-Access                      ANSI SCSI revision: 02
Attached scsi removable disk sda at scsi1, channel 0, id 0, lun 0
SCSI device sda: 253952 512-byte hdwr sectors (130 MB)
sda: Write Protect is off
 sda: sda1
WARNING: USB Mass Storage data integrity not assured
Now I just mount it on /dev/sda1. Still, it is bit weird why it went to sda1. ...