UPDATE: Thank you for everyone's participation. I have added several tips based on comments in the discussion
1. Copy MP3 or WMA to Zune Collection. Choose Edit, and type in manually under Genre "Ringtone". The song must be less than 40 seconds and smaller than 1MB.
2. Go to Settings -> Ringtones + Sounds, tap Ringtone. Your custom ringtone will appear under a new tree called "Custom", above "Windows Phone"
Note that it is identified by the filename, rather than the track title.
Also, you can tap and HOLD a ringtone, and Delete will be offered (but only on the Custom ones; preloaded ones grey out delete).
Windows Live Messenger
Windows Live Messenger is so damned easy that I didn't see it staring at me. Pick Messaging, slide right to Online. Set Chat Status (icon at bottom), hit +, and send a message to any Messenger contact. And/or if anyone sends you an MSN, you get a ding just like a SMS, and it appears under Messaging.
Mango automatically made my Windows Live account that my phone is registered under, which is also my Messenger account, work. Others have noted that it's not possible to have a second Messenger account -- only your PRIMARY Windows Live account is linked to Messenger.
Facebook chat is set up also from Messaging -> Online. Some people have had trouble with this... read down to see some possible solutions.
Dev Unlock Mango B2
You must have a dev unlocked phone to install Mango, but installing Mango relocks your phone. To unlock it again, run Windows Phone Developer Registration from the Beta 2 SDK tools.
Voice Activated SMS/Messaging
To allow Voice recognition from Messaging (like SMS, Messenger) while on Carrier Data, go to Settings -> Speech and check Enable Speech Recognition over Network.
This is REALLY cool. Put on a headset; leave your phone on the home screen. When someone sends you a Messenger, it announces that the person has sent you a message, Read It or Ignore. If you say, "Read it", the phone reads the message. You then have an opportunity to reply via speech!
Evidently, this is in Settings -> Phone (or Phone app, slide up, call settings). But it doesn't show up for everyone -- it's carrier dependent (doesn't show up for Telus phone on Fido for me).
Exchange/Gmail Server Search
To search the server for older (for example, Exchange) go to Outlook, click the on-screen search button, make a search. At the bottom of the results, tap "search more in Outlook". When the server search is done, at the bottom of the results, you'll see "get more results" and "search all folders". Woohoo!
Bing Visual Search -- and OCR!
Tap Bing key. Click eyeball. You can snap QR codes, Microsoft codes, or TEXT. If you snap text, it will then detect it, and you can translate it (for example, from French to English). But as someone mentioned, you can translate from English to English... and the results come as text that you can then Copy and Paste! Quick and easy cloud OCR that you have to see to believe.
Go to Office. Slide over to Locations and SkyDrive. You can see any of the documents on your SkyDrive, and edit things like Word. It's perfect.
Notes (OneNote, synchronized with SkyDrive and your Desktop OneNote as long as you're saving to Web) is really slick. Office 365 and SharePoint are under Locations.
Music Controls - This one's easy. Play a song, pause it. Hit lock key. Controls are on the wallpaper. Unlock, hit volume keys -- Controls appear.
Multitasking - Hold down Back button. It's a beautiful implementation. To remove a task from the list, pick it, then hit back button once.
Outlook Threads - Just tap a conversation thread to expand it.
Outlook Account Linking - Outlook -> ... -> Link Inboxes
App Grouping - tap the letters above the groups of apps, just like the phone book (tapping "a" gets you all the letters, tapping "s" jumps to Settings)
App Find - tap magnifying glass on apps list
IE9 -- OMG. Best Mobile Browser Ever. 'nuff said. But is it possible to turn off Address Bar in Landscape? Takes up lots of space.
People/Groups - Tap People hub, tap Family or +. You can make your own Groups, and then SMS or email everyone in the group that has SMS or email. Or quickly call them, since they get big tiles.
People/History - Tap a contact in the People hub, slide to the right, and see History. It shows call/messaging history, and "search Outlook" at the bottom.
Really Nice Subtle features
- Improved buttons during a voice call (larger, blockier, and harder to mispress)
- People Tile is really pretty now
- XBox Live Hub, Avatar, Messages -- way, way nicer. Best game hub ever.
- Marketplace is much better organized; Games are split up into categories.
- Power Down (hold lock button) now "confirms" with a prompt to slide down
- Hardware Search button now always brings up Bing; on-screen search button for context-sensitive.
- Dithering on browser eliminates banding in most cases
Doesn't Work Anymore
The following appear to be broken in Mango:
- Homebrew - Chevron Ringtone Installer (but it's bult in now)
- Homebrew - Home Screen Bluetooth/Wifi/Data button (I already miss this one!)
- LG App Store doesn't seem to open anymore (error appears -- but this seems to work for at least some other people)
- Maps Directions gives an Error
- Maps - Some people don't get Traffic, others do. For the time being I am using gMaps. Free version works!
- Not really sure how to go back and forward on the browser, other than "recent" (which doesn't give you cached version).
To make Traffic work, just set region/location to English (United States). I had it set to English (Canada). Directions from "My Location" then works as well! (note that I am physically in Canada).
LG App store still does not work for me. It comes up with Error code:805a0194 (Optimus 7 / Telus)