dzMdbViewer is a small tool I wrote, when I was stuck without a MS Access installation but needed to have a look into a .MDB file (and later .ACCDB file, if the Access Database Engine 2012 is installed).
It can open these files and display a list of queries and tables stored in them as well as the data they contain.
Also, for tables, it can show the field definitions.
Today I added support for command line parameters, so it can be used as the default program for opening these kind of files. Download it from SourceForge. The source code is available too. (I got tired of the inconveniences of Mercurial, so I moved this project to Subversion.)