My tip this week is buy rechargeable batteries. We have just got round to doing this, I think both the poor experience in the dim and distant past and the fairly hight initial cost has made me hesitate up to now. Having looked in to it we made the leap and bought a charger and some batteries. It did make us stop and think how many batteries do we actually need? Thankfully not many, perhaps a result of de-cluttering over the years.
It can be a bit daunting deciding what to go for, there are more options that I thought (you can even get 'Hybrio' batteries that come pre-charged and keep their charge for about a year!). Battery Logic have a good site explaining everything. I didn't realise that rechargeables can actually outperform disposables by 10-20 times in things like digital cameras (as longs as you buy the right ones!). As for makes, Uniross are seem to be the largest, a name I remember from the early days of rechargeables. We actually went for Ansmann, they cost slightly more (not much) but a number of places seems to recommend them over Uniross and they have won a lot of awards.
Choosing the make you want to go for is the first step, then you need to decide the power rating of the batteries you need and the type of charger (fast, slow, intelligent...). Basically get as powerful batteries as you can afford and the best charger you can afford as it will look after the batteries. Don't go for a super fast charger unless you really need it as the slower the charge the better for the battery in the long run. We spent £60 on a good charger and 12 batteries that will last 1000 charges each. That's 0.5p per battery if you had to buy the equivalent disposables!! As we use 100% green electricity (see Utilities) so it is even more environmentally friendly.