This is a bit different but it still means a lot to us. DH really struggles to fit regular exercise in as afternoons he is always held up at work and works so late through the night that he can't get up early to exercise. Recently we had a child free night and got up to do a powercamp together. DH really liked it, but knew he wouldn't get to it again. Anyway, the trainer offered to train with him as 'training buddies' on a weekend so that DH can get some regular exercise in, free of charge. We barely know this trainer, so it was really nice of him to offer a suitable alternative to DH.
And one where I helped someone else: I was at the airport seeing my dad off as he was going to a funeral. We watched this woman as she was trying to offload her luggage on to the security thing to be scanned but every time she put her toddler down she'd take off and the mum would have to dump everything and run after her fast toddler! She was laughing, but security didn't offer to help her at all and she was clearly on her own. After the second dump and run I went over to her and told her I'm a mother of three and would she like me to either hold her daughter or put her luggage on the conveyor belt for her. She thanked me and handed me her toddler and loaded her luggage.