If you're using MInt 7 it's ctrl + super l. You can set your preferred combination by right clicking the menu button and selecting preferences.
menuhin wrote:Also, can I really use the filter in mintMenu like spotlight of OSX or make it behave like that? --- e.g. type "firefox" and then press ENTER to trigger firefox...
That doesn't seem to work but you can press alt+F2 and type the command to start a program. Most programs start command is their name (ie firefox=firefox) but some are more complex (Calc = ooffice --calc, same syntax for writer etc)
Or better yet use gnome do instead of alt+f2. Set it to start at startup, then you can summon it with super+space. Then firefox = "firefox", calc = "spreadsheet".