Quick notes on apps I’m using with my E71 smartphone:

• Nimbuzz and Fring because (unless I’m being really dense here), Skype Mobile doesn’t support free skype-to-skype calls over WiFi. I’m using Teliax as an SIP provider. (This would give me a cheap option on the move, as well as a Vonage/Skype backup at home since one of my routers does SIP too.)
• Gmail with sync’ed contacts and calendar using Mail for Exchange and Seven (which might actually be enough to handle push). Nokia Messaging but doesn’t recognize Gmail labels as directories, while the Gmail app

  doesn’t do push. I’m not able to push the new tasks in Gmail yet, but email/contacts/calendar is quite nice already.

• Opera Mini and Skyfire browsers. I love to multi-task between browsers, this is my mobile version of tabbed browsing.
• Sports Tracker.
• Nokia Maps (I rolled back to 2.0 from the 3.0 which didn’t work for me – how to download maps) and Google Maps. You can use Nokia Map Loader to give you great offline support on your phone.
• Extra dictionaries.
• Newsgator Go which I’m not in love with, but I like Newsgator Online and obviously I want subscriptions and read/unread status kept in sync. It’s got caching which should be useful to have stuff to do while offline.
• Devicescape Easy Wifi so that various applications don’t have my home WLAN hard-coded in their settings.
• Nokia Location Tagger to geotag pictures on the fly.
• Though not technically an application, I like dabr for Twitter mobile access.
• Youtube Mobile Application is nice though limited, but I’ve never been a Youtube power user anyway.
• Jbak TaskMan

I’m planning a trip to the US in April/May (Denver and Miami) and want my phone to support me as much as possible during the trip. I usually rely on a good old piece of paper with all the necessary addresses and phone numbers and what not, but I hope it will act mostly as backup from now on.
Update: I’ve set up Teliax and made a couple test calls, seems pretty good so far. Vonage has seemed on the brink of extinction since pretty much they got started and Skype has never worked quite as well for me (some calls are great, some are crappy, it’s always been more uneven in my experience). Plus, Vonage’s soft phone is not cheap and I’m not sure there’s even one for smartphones. More options means more resilience means less headaches and downtime.
Also: E71 tricks.
Update about push email: Seven sends SMS to the UK in a kind of sneaky way behind your back, and it doesn’t work seamlessly with Devicescape Easy Wifi (at least for me). Not sure it’s going to be my long term solution, especially given it won’t work with messages stored on external memory. I tried Emoze but it doesn’t seem to manage folders, at least not the free product. Next: Profimail.