I have a 2007 Rev. A 24" aluminum iMac. I haven't upgrade to 10.7 because I am upgrading my machine in the next week or two. So it got me thinking about what things I would do to prepare. Since it is not just an upgrade (though some of it might apply to those upgrading existing machines), this is a great opportunity for a spring cleaning. After all, what's the point of bring over a potentially cluttered data set with apps and other items that are either never used, not needed, or otherwise in disarray. 1. Update all apps to the current version. Personally I use MacUpdate Desktop for this. I know the Mac App Store keeps you up to date on apps purchased through it, but most of my apps I acquired long before the MAS. Of course RoaringApps.com has a great compatibility table for apps in Lion, so check that out too. 2. Organize the user directory, especially the documents folder, any desktop folders, and the sometimes overgrown downloads folder. 3. Clean up iTunes tagging. If your iTunes library has been cleaned up in the past, this should be minimal. But also cleaning up folders, playlists you don't use anymore. 4. Go through your iPhoto and/or Aperture libraries and clean up rolls, delete blurry photos from imports you didn't get around to. Etc. 5. Mail. I tend to keep my mail inbox and subfolders pretty tidy. I like a relatively empty inbox. But this is your chance to reduce clutter. 6. Safari. This is a big one. I am looking forward to reading list as I often bookmark stuff for either reading or reference and never get back to it and I hope reading list will help me manage that better. But I know my bookmarks are poorly organized and could use a thorough combing. 7. That is really everything I can think of, but will append this list with suggestions. But that brings me to the most important items. Verify your disk. Repair Permissions. And back up, back up, back up. In my case I use Carbon Copy Cloner to make an incremental clone of my iTunes 2TB media drive to an identical 2nd 2TB drive named iTunes Backup. And I use Time Machine to backup my internal 750GB to a 750GB for TM. Migration Assistant However, this brings me to my next point. Which is actually more of a question. Now I personally don't know how well the Migration Assistant has evolved over the last few OS releases. But I didn't like the idea of such a wholesale data migration. As I understand it, you have more control over what gets copied, etc. But I still feel somewhat cautious to the idea of bringing whatever baggage in buried in the file structure, settings, etc. with me to a brand new machine. My take is it may take a bit longer, but I prefer to download the latest versions of my apps (after all I have the serials) and then copy my iPhoto library, and the contents of my user folder over using a firewire cable and target disk mode. My iTunes media drive will simply be connected and iTunes asked to locate the folder (though the iTunes library file will need to be copied from the user folder). Is this overkill or just good sense. Would you go ahead and use Migration Assistant or do you prefer a more pick and choose hands on approach to migrating to a new Mac? Thanks for reading, let me know what you think and anything else worth noting in the prep points. Remember many of them are good even if you are just upgrading your existing machine.