I've used Slides a few times for presentations. Works really well for creating quick internal presentations for team meetings, etc. I'm still hooked on Keynote though for more elaborate stuff. At GoInstant we actually had some fun with the underlying Slides tech (Reveal.js), which is an open source library for the presentations, and made them multi-user -- http://gordienoye.github.io/go-r... -- was fun to play around with.

@byosko +1 to reveal.js I love how I can write my slides in markdown and have reveal js take care of the presentation

is this a dupe?

I love slid.es use it all the time : https://slides.com/troomobile

GREAT for simple/small presentations. Tough once you exceed 10-15 slides though.