I took the kids to the Discovery Science Museum in Santa Ana yesterday. It was a great way to spend a few hours on a cloudy day. My 16-month old loved the "toddler" play area (slide, puzzles, dress-up area) and my 3 1/2 year old enjoyed the special exhibits (Clifford the Big Red Dog, brushing giant teeth, sand/wave exhibit). Unfortunately there were a few school field trips there at the same time, which got crowded and overwhelming for my kids at times. They are having a bubble exhibit starting mid-March which we've been to in the past, and is definitely worth checking out!