After tossing two plastic baby bathtubs to the curb for Brooklyn-style freecyling due to their obnoxious size and my son's displeasure with a pre-formed mold of how to lay in a bathtub, I've turned to a bath seat. There are very few bath seats out there (and I'm not sure why), and the Dream Baby Fold-Away Bath Seat is tops as it allows your baby to sit without your active support and folds up flat. I've got another month or so before I can test it out--Devin needs just a tad bit more sit-up strength before it's gonna work for him--but I have high, high hopes.
