Help From Home http://www.helpfromhome.org/ provides information on simple, no commitment volunteering opportunities including those that are similar to Oxfam's objectives.
The actions can all be performed from the comfort of your own home and most will cost you nothing or very little to complete whilst taking no more than 30 minutes to accomplish – some can even be performed in under 10 seconds! You don't even need to get out of your favorite chair or pyjamas to perform most of them.
These actions really can make a difference, not only in the area that you live, but also nationally and globally as well. So, put on those pyjamas and see what you can do for your community and beyond.