If your tyke is a little trekker, then you might want to consider the new Star Trek Uniform onesies from ThinkGeek. Whether she has the makings of a science officer or he has a penchant to boldly explore new territory, ThinkGeek has a uniform just for them. Four different onesies are available: Indigo (science), Gold (command), Red (operations), and Grey (cadet). Each outfit retails for about $15, with sizes for children up to 24 months. The outfit includes a snap bottom closure for easy access.
Want an adult version for yourself (sans snap enclosures)? Yeah,ThinkGeek has those, too.
Kids onseies available from ThinkGeek. Retail price $14.99