Here's a little tiny SMPS - 120VAC (USA spec) -> 5V@2A for a USB2 hub. That's a standard T-1 LED and the foreground schottky diode is in a standard TO220 for size comparisons. (#*@#% hub died on me... Grr.)
In the foreground you can see the secondary rectifier diode and low ESR filter caps, the black cap that's on its side is the input filter. I didn't spend too much time figuring out what everything is, but the LP-0520T04 is the flyback transformer, and the switch mode transistor is right behind it on the other heatsink. A filter/PPFC choke is towards the back.
I'm quite surprised they make stuff like this now, but it's about time. There's no way to get 5V @ 2A from a linear this small and weigh so little...
(Oh, as for the reliability aside, I've never had a low frequency transformer+rectifier+linear wall wart die on me, but I've had these small SMPS die on me before... hence questions about reliability.)
Are there any other small, light, high power topology that's not a SMPS? AFAIK I don't think there is, but, I'm curious... Pictures would be nice!