I was initially confused by your post because I thought you were talking about a MyMagicExperience account (which you set up through Disney). I was like...."Don't you kind of need one of those to make your dining reservations and fast pass reservations? How does that help you save money---oh."
And then I got it.

You mean a separate bank account.
Yes, yes I do. I learned in my early 20's that the "envelope" system was a great way to be semi-financially responsible. I'd take $60 from each paycheck, and divy up $20 each for three separate envelopes (wedding, Christmas, and one day having a kid--LOL!). As I got older (I'm 30 now), and when I broke up with the guy I was with at the time...I realized I probably wouldn't have kids, and that I'd never get married. I kept the Christmas envelope though, because I liked the idea of knowing how much I'd have for Christmas every year--and KNOWING I had it.
You get older though and realize, "Hey, gee! It's really easy to steal from an envelope if your house gets broken into" and stuff like that. So, I, as you have discovered, created an electronic envelope system by opening up several new accounts through my credit union. While I've done away with the "baby" savings (DF doesn't want kids--sad!), I do have money market accounts set up for both my Christmas savings and Disney (though right now, it's labeled "Disney Wedding/Vacation"--because they're kind of synonymous for our Florida trip!). Each check, I have an automatic transfer to both.
As much as it sucks to see it go from my checking account...I'm really excited for pay day to see portions of the check go into savings for those other expenditures. It DOES create a sort of peace of mind to be like, "Okay--I KNOW how I'm going to pay for this now."
Well, sorta.

I know Christmas is covered. The wedding? Meh...we'll see. I'm kind of sad I won't get my BEO until mid-late October now (which throws off my savings attempts a bit, because I don't know how much I'll really need)...but I will say it certainly helps to have a lot in reserve!
Tiffiny