I was really upset to find that there was no way to just mount the internal HDD of my iconia in ubuntu to copy music/pics/movies across to it.
After a bit of googling and fiddling, i managed to get it working.
**DO NOT use “sudo apt-get install mtpfs” To install MTPFS, there is a bug in the repo versions that cause it to not mount your iconia (which i found out much to my dismay, and wasted time…)**
1)Download MTPFS From the debian package repo (Make sure you grab the correct one for your architecture.)
You can find out which architecture you are using, by running “uname -a” in the terminal. Here is an example of the output
jon@jon-laptop:~$ uname -a
Linux jon-laptop 2.6.32-28-generic #55-Ubuntu SMP Mon Jan 10 23:42:43 UTC 2011 x86_64 GNU/Linux
jon@jon-laptop:~$
NOTE THE SECTION IN RED
As im running the 64bit version of ubuntu, i obviously grabbed the amd64 version.
2) Install mtpfs, Do this form the terminal:
cd /home/jon/Downloads
Sudo dpkg -i mtpfs_0.9-3_amd64.deb
3) Turn on USB Debugging on your tablet
Apps > Settings > Applications > Development >Tick USB debugging
4) Now you need to find the vendor ID of your tablet. So go ahead and plug your tablet in, then open the terminal and type:
lsusb
You should then get output similar to the following
jon@jon-laptop:~$ lsusb
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 046d:c408 Logitech, Inc. Marble Mouse (4-button)
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 015: ID 0502:3325 Acer, Inc.
Bus 002 Device 002: ID 04f2:b044 Chicony Electronics Co., Ltd
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
**NOTE: The section in red is what we need to be concentrating on
** You also now need to disconnect the cable**
5)Now we need to create a UDEV rule file using the following command in the terminal:
sudo nano /etc/udev/rules.d/51-android.rules
You Then have to fill that file with the following:
SUBSYSTEM==”usb”, ATTR{idVendor}==”0502″, MODE=”0666″
6) Now we have to make our mount point and put the correct permissions on it:
sudo mkdir /media/a500
sudo chown user:user /media/a500
**NOTE THE SECTION IN RED, you need to change that to your user and group, on a home install, its usually username:username, so mine was jon:jon.
7) Now we need to add our mount point to /etc/fstab, So in your terminal, put the following:
sudo nano /etc/fstab
You then need to add your mount point to the end of the file
# mount point for Acer A500
mtpfs /media/a500 fuse user,noauto,allow_other 0 0
8 ) Now we need to make a quick change to the fuse.conf
sudo nano /etc/fuse.conf
Look for #user_allow_other and remove the #.
Also, add yourself to the fuse group
sudo nano /etc/group
Just look for the line fuse, and add your username, heres mine:
fuse:x:104:jon
9) All thats left to do, is reboot. Once that is done, you should see “a500″ in your “Places”, jsut connect up your tablet and away you go 
Jon