Here's possibly what you want. Works for me perfectly
First you need to install (other similar programs available too) xbindkeys
sudo apt-get install xbindkeys
Then create a default configuration file with
xbindkeys --defaults
(Prints the default configuration file)
So to create a configuration files with default values run
xbindkeys --default > $HOME/.xbindkeysrc
Using ctrl+alt+T is not recommended in this case, since it is already in use. Find a unique key combination to use. I personally chose ctrl+shift + aring
You may want to use the following command to see exact names of the keys used
xbindkeys -k
After running the command, you need to hit the key combination. You will see an output similar to this
m:0x5 + c:34
Control+Shift + aring
Then edit the configuration file you created with an editor of your choice
vim .xbindkeysrc
You will see that the only lines that are not commented out are
"xbindkeys_show"
control+shift + q
That's one existing key combination
Add the following lines below the above mentioned lines
"gnome-terminal --working-directory=/home/$USER/Desktop"
control+shift + aring
(If you used different keys, add those instead of control+shift + aring)
The file around that area should be looking something like this
# Examples of commands:
"xbindkeys_show"
control+shift + q
"gnome-terminal --working-directory=/home/$USER/Desktop"
control+shift + aring
# set directly keycode (here control + f with my keyboard)
#"xterm"
# c:41 + m:0x4
Save the file. After saving, you need to run the following command to activate key shortcuts for the session
xbindkeys
Now with the combination you set you should be able to open gnome-terminal to Desktop directory
Note! Using xbindkeys is explained very well and in more detail here
How can I change what keys on my keyboard do? (How can I create custom keyboard commands/shortcuts?)
See Seth's excellent answer on that