How to write options lists with drush vset? When we want to pin a variable for an environment, we'll set the value in the admin, then go look it up in the database, and copy the name and value into a bash or phing script, to insure that that variable is always set to the appropriate value for the environment.  

However, for complex variables, such as options lists, what should set string look like?   For example node_export_file_types looks like this in the database:

a:29:{s:4:"blog";s:4:"blog";s:10:"case_study";s:10:"case_study";s:7:"analyst";i:0;s:5:"asset";i:0;s:4:"book";i:0;s:6:"course";i:0;s:8:"download";i:0;s:8:"employee";i:0;s:19:"evaluation_download";i:0;s:4:"news";i:0;s:17:"front_page_header";i:0;s:11:"hero_banner";i:0;s:12:"landing_page";i:0;s:11:"layout_page";i:0;s:10:"news_event";i:0;s:10:"news_press";i:0;s:7:"product";i:0;s:16:"product_overview";i:0;s:17:"product_resources";i:0;s:15:"product_webinar";i:0;s:8:"workshop";i:0;s:12:"registration";i:0;s:8:"resource";i:0;s:7:"license";i:0;s:7:"support";i:0;s:16:"training_courses";i:0;s:16:"training_request";i:0;s:17:"training_webinars";i:0;s:7:"webform";i:0;}


if we wanted to set that using
drush vset node_export_file_types 'somestring'
what that 'somestring' look like?
You can use drush.

drush vget foo --pipe

The --pipe option will format the output as php code.

As far as using that with drush vset, I would recommend against that and instead set via an update hook, or directly in settings.php.