We go through batteries so much that we decided to take the plunge and invest in a rechargable kit. We found a really good deal at http://www.all-battery.com/ and purchased this set: T-6280 8 Channel Smart Charger with 16 AA 2600 mAh NiMH Rechargeable Batteries. Total price was $40.99, found a coupon from searching them on google for free shipping (coupon code tenergy2008). That recharger says it can rechage a 2100 mAh AA battery in about 3.5 hours. I found a couple 8 battery recharger kits for a little less but the standard recharge time was 8 hours. 3.5 hours seems so much better. We also dont use as many AAA as we do AA so I went with the kit that offered 16 AA instead of 8 AAA and 8 AA.
Anyway, will let you know once we get them. Just thought that you may go through a million batteries a day what with all the noisy light-up toys now. Or maybe you don't care and take time to relish the peace and quiet when they die...to each his own :)