KFCon, by data do you mean calendar data or mostly just what is in your contacts / database?
Each of the databases should be easily enough exported in a form that ACT can import as it can import about anything.
You'll simply export each database file as a .csv (as James33 has described in various posts here) then just arm-wrestle with ACT to get them imported.
Dealing with calendar stuff etc I have no advice for unfortunately. But one thing I DID want to comment on, and this may be too late if you are committed on ACT, is how terrible the reviews have been on that program for the last several years.
I have been tempted to convert over myself! But man, look at the reviews on Amazon's software area, they tend to be "very honest". Bluntly terrible for the 2006 and the 2007 (newest) ACT. Each version, 2 stars out of 5, with absolute horror story feedback compared to older versions.
So, us Sidekick people aren't the only ones cruising along on older versions of SW, LOL. But with the calendar / time related function issues with Sidekick, I fully understand the need to move on. Re: simple basic database functions, after trying many things I'm staying with Sidekick 98 for that, frankly avoiding either horror story feedback (with many programs) or simply poorer design / features / ease of use (database context here) compared to SK 98.
Long live the drifting Sidekick...
Frank H.