I use Outlook 2007 both at home and work, but the way I handle my email at each location is very different.
I work for a fairly large company (4300+ employees) and there are policies and procedures put in place by our IT department (at the direction of our Legal department) that dictate how our email is handled. Each week, email in our Inbox and Sent folders that are older than about 2 months are purged and moved to a temporary trash can. We can retrieve those messages during the next week, but then they are gone. Email that we have filed into folders (either by moving it there or by the use of rules) is similary purged if it is older than 18 months. Same deal applies - we can retrieve it during the following week, and then it's gone.
The whole process is built around corporate document retention policies that take into account what can be considered "corporate records". Implicit in the policy are considerations about legal "discovery" procedures, etc. We are unable to archive email, move it into folders outside of Outlook, etc.
I do move email into folders according to projects, or topics, or by organization. I manage an R&D program and do a lot of projects with universities, national labs, consultants, etc. I do use some rules (for newsletters and other regular bulk mail), but for the most part I manually move email into folders. I also make pretty regular use of Outlooks ability to convert email into calendar appointments and tasks.
One product I have used for several years that I have found very useful is Nelson Email Organizer (NEO) http://www.caelo.com/index.php
Makes it easy to see email from a particular sender (no matter what folder it's in), see all attachments, find by date, etc. Also has some easy ways to make rules.
At home I use a similar process, but use a lot more rules. I also don't have to worry about how long I keepstuff. We get a lot of email related our kids' school, shopping, banking and investments, books, newsletters, etc - so most of that stuff is handled by rules. With earlier versions of Outlook I used a spam filter (using whitelists) called Qurb. http://www.qurb.com/
It looks like they were bought by CA.