If you are looking at replacing the AAA Maglite, I'd recommend taking a look at the
Fenix E01 for $15. I've been using one for a while now and have been very happy with it.
While the Preon ReVO seems to be very cool and loaded with extra features and capabilities, at $47 its a bit more than I'd be willing to pay for a small flashlight.
Actually, for only a bit more than the price of the Prion ReVO, I was able to get each member of my family their own E01 for their lanyard or keychain (and only one has been lost so far!). The lower price also makes losses more managable
.
For size comparison, I found the following picture with both a Maglite Solitaire and a Fenix E01 in a
review for the E01:
According to the specs I found for the E01, the E01 and the ReVO are pretty much the same size (2.8" x .5").