It's called "Baby fever". Every crafter knows what I'm talking about. As soon as you hear that someone you know is having a baby, it begins: you plan your projects, you buy the yarn, you browse through thousands of patterns and finally you roll up your sleeves and knit/crochet. Add someone you really like into the mix and multiply this for a thousand.
This is my take of the Snug as a Bug Sleep Sack, by Robyn Devine.It's avialble as a free Ravelry download (here) and it's pretty straightforward, just the kind of pattern I like. I didn't have to make any mods whatsoever! To maintain my level of sanity, I used a self-striping yarn (Drops Garnstudio Fabel Print, colourway 677, purchased at Bolas de Tons) and I think the end result is pretty nifty. And I only used 1.5 skeins, so I'm sure I still have enough yarn for a pair of matching booties, for instance. The buttons are also cute, just right to keep the little dude warm!