my DH came home from work this morning and said "Why don't you and (adult) DD pop into town and have a nice coffee and relax. I'll deal with DS3 and then put him down for a nap later this morning. It's Friday, and it's not going to hurt me to lose a little bit of sleep - you need a break!" 
Lovely man!! I have been stressed to the eyeballs lately and REALLY needed this! So DD & I went into town (after school run), had a browse around book shops (a big no-go with the little ones, they get too impatient or want everything!), and then had a lovely coffee (gingerbread latte yummmm!) and chatted.
We arrived home just as DS3 was waking up from his nap. Perfect timing and a lovely morning!
It's amazing how just a short morning's break like that will rejuvenate!! Sometimes it's something simple like taking a long hot bubble bath with a glass of wine and a good book, while DH takes over "child duty" for an hour.
So... what little breaks have you had recently - or are you going to have - to retain that all important sanity?