I have been reading around this Thing for a while before I actually tried to write anything. I find myself sitting on a fence: I think the idea of volunteering for experience is a good one but it excludes those who can't manage to sustain themselves financially while they do it and that is a very bad thing. I hate the idea of cutting back on paid librarians to staff libraries with volunteers but if that is the only option on the table, isn't it better than nothing? When do you accept defeat and seek damage limitation? No easy answers to these questions for me.
I have only done a little volunteering in recent years (I did a lot as an archaeologist back in the 90s!) - at the moment I do a few bits of work for our local community woodlands society. I do that because I like the woods and want to contribute something to the local community, however small. For me, the important thing with any volunteering is to be realistic about what I can manage and only offer to do things that I can fit into my limited spare time. I find it easiest to do web-based stuff - not attending meetings or events so much unless the kids can come along too.