Hi all,
I used TENS most of the way through a long labour and found it really helpful. After a few hours of breathing, rocking, massage and hot water bottles it seemed to do the trick, especially when we increased the levels slowly. My husband did all the positioning of the electrode thingies (guided by me) and I tapped him as the contractions came on and he pushed up the intensity. As the labour progressed and I began endless pacing around the birthing room, he followed me with the controls and I called out "More juice honey", which eventually shortened to "JUICE!!" as the hours wore on. We got into a pretty good rhythm. Apart from not being able to use it in a hot, hot shower (which I reckon is the best for the pain, apart from an epidural of course!) I found it quite useful; the buzzing did distract me from the pain.
Of course, everyone is different - for me the gas did nothing - but I do think that it's useful to have as many different options up your sleeve as possible.
Anyway, hope that's helpful!
Bid