To show what is possible with a 5V Trinket running at 16.5MHz check out this simple implementation of the Trinket as a keyboard input device:

Which is to say the 3V and 5V Trinkets are very similar, save the logic voltage of the two devices.

This specific project assumes the 3V Trinket is used with the LEDs and resistors shown – the 5V Trinket is also applicable but would require changing the resistor/s required. This allows Trinket projects to be quickly prototyped. The Trinkets are breadboardy-ready, which we all typically have plenty laying around. To get you started with seeing how easily the Trinket can be deployed for projects, check out this Blinky Eyes Learn Guide – replace a full-sized Arduino with something much more discreet for something so simple and specific: It’s our lowest-cost arduino-IDE programmable board! Perfect for when you don’t want to give up your expensive dev-board and you aren’t willing to take apart the project you worked so hard to design. We wanted to design a microcontroller board that was small enough to fit into any project, and low cost enough to use without hesitation. Trinket may be small, but do not be fooled by its size! It’s a tiny microcontroller board, built around the Atmel ATtiny85, a little chip with a lot of power. Today we’re profiling our own line of Trinket development boards.

Adafruit trinket 5v keyboard