lp.scampi has ceil, floor, trunc, round, and toinf modes for converting floats to integer.
Max 5 users will want the version of lp.scampi in the Litter Pro Bundle. Lp.scampi is also included in the free Litter Start Pack, but the Starter Pack is really only happy in the Max 4 world. I may get so tired of writing this caveat that I get an updated, Max 5-friendly version of the Starter Pack out. Still, there *is* always the Pro Bundle, which is quite happy in Max 5.
Using 0.4999 works (for most uses) but 0.5 will round any integer up to the next integer instead of staying unchanged.
Incidentally I am looking for a floor/ceil object. I have to say it's quite annoying searching around for such basic things when they could have been implemented easily in the round object to begin with...