You can do this in a variety of ways from using Particle Playground, Card Dance, Shatter to CC Particle World to third-party plug-ins such as Trapcode Form and Particular. There just won't be any instant solution with either of these. All of them require multiple instances, custom parameter maps and/or heavy parameter animation as well as time-reversal techniques since naturally most particle systems expand/ explode ratehr than to "suck in". realyl depends. i recommend you study the VideoCopilot site's tutorials section, Tuts+ and other resources. and look for something suitable to get started, then come back with more specific questions.
Thanks for the tips i'll look into those. I normally use Maya for this kinda stuff (i've already used it for some explosions on this project) but i want to try new methods.
If anyone has any other simple explanations that'd be great.