Golf ball finding devices?

Other than the traditional method of using eyes or better still playing well and keeping ball on fairway and then green anybody had any experience of these?

A bit of research suggests: http://www.radargolf.com http://www.ball-finder.com looked promising on paper but just did not seem to work and/or take off. In fact the latter (Ballfinder Scout) seems to have had the worst of reviews of any gadget I can recall - despite Nick Faldo apparently endorsing it.

The former had a chip in it presume never gained ground as you would have to use their special balls.

A less techy idea seems to be blue tint glasses - http://www.amazon.co.uk/dp/B000L1EO4Q/ref=asc_df_B000L1EO4Q8070193?smid=A3P5ROKL5A1OLE&tag=hydra0b-21&linkCode=a
sn&creative=22206&creativeASIN=B000L1EO4Q&hvpos=1o2&hvexid=&hvnetw=g&hvrand=594423043888569983&a
mp;hvpone=&hvptwo=&hvqmt=

again with somewhat mixed reviews.

For some reason best known to her, my wife bought me a Ballfinder Scout for a birthday present a few years ago. It was total garbage!

Please, never never never buy one!