I recently had the need of a laser measure & invested in a Bosch PLR15. Not the top of its league, as it's maximum range is only 15 meters, but I had no need to splash the cash for what I needed, and what I got was exactly what I needed. It's compact. 100x36x23mm and weighs 0.1kg. It runs off 2 AAA batteries, supplied & comes in a nice storage tin. Being used to longevity in battery powered things, I was surprised to find that the life is only 5 hrs, but as that's in measuring operation mode I suppose it's going to be sufficient for most projects. You get a warning that the battery is on its way out when the battery symbol appears, after which you've got 15 mins before shut down. Alkaline batteries are stipulated and top tip don't use rechargeable ones. Standard batteries are 1.5 v each, rechargeable are 1.2 so where multiples are used the power drops off quite quickly and might not work. There is the usual on/off switch, but a nice touch is the "hold" facility. An extra push button which allows the recorded distance to be held. Ideal for when it's held out of eye sight of the screen. The length of the device is taken in to account when measuring, so you simply hold the back against one surface, shine the laser onto the one your measuring to and what appears on screen is the total distance. I measured on a normal day with both steel tape and the laser, and found it to be spot on. During extremes of temperature there is a warning that the device should be allowed to adjust to the ambient temperature where it is to be used. Operating temperatures are -10C and +40C so as far as the UK is concerned there should be no problem year round. The thing to remember about lasers are things which may influence their accuracy. Lighting, transparent surfaces, reflective surfaces, can give false readings so one of these may not be for you. However, I feel that under most circumstances it will prove to be very handy, especially if there's no one to hold the other end of the tape, or where the other end is out of reach. Prices, as for most things, can vary widely so it's a good idea to shop around.