One of the coolest toy I remember owning as a kid what the Batman Utility Belt from Remco released in 1979. It came with a Bat-watch, Bat-walkie talkie, Bat-glasses, Bat-handcuffs. It was amazing! I remember pretending for hours to be Batman.
This kit can still be found mint and inbox on sites like Ebay but last time I checked it was around $500 US, talk about crazy but I'd probably buy it over an Apple's iPad.
Remco made other very cool utility belts "based" on Spider-Man, Hulk, Captain America and Superman. Remco was a toy company founded in the 1940s that was best known for toys marketed and sold in the late 1950s and 1960s.