I like to keep my personal and work emails separate. But I'm beginning to think the best way forward might be to just use one email for everything. One of my big fears though is that if the Google ban hammer falls on any of my Google accounts (adsense, adwords), it might literally jeopardise my life.
I had to download another webbrowser to read my company email (google apps) because my main Safari is logged into my original gmail account (because that's where reader is logged into and it's what I will use once the eventual Google+ invite arrives).
If someone at Google is reading this: Please, please, please implement multiple sign-in for mobile browsers. As it stands now, the (excellent) webapps for calendar and mail are next to useless for me (and I'd guess a lot of other people)
For outgoing mail, add your apps account under "Accounts and Settings > Send Mail As" and check "Reply from the same address the message was sent to."
I have 3 apps accounts and 1 personal account. This has worked out pretty well.