Whats your current "can't live without app"

Hi everyone.

Do you have any suggestion on apps that you cannot live without?

1. "Launcher Pro": For faster and smoother scrolling
2. "Installer": For installing outside files other than android market. It scan searches for execution files that you downloaded or transfered over from PCs.
3. "Free Memory": It frees out unwanted memory every 1~30minutes time frame constantly. I have no issue of lagging after installing #1 & #3

*update
After using "Free Memory" for 3days, I experienced some unstability on my phone.  It was uninstalled

+1 for Launcher Pro and Appbrain.   Also add Astro File Manager, Jorte, and K-9 Mail
If you are coming from WinMo  OfficeSuite Pro is a good one, but not free. 

Dropbox; now I automatically have ALL of my Word and Excel files, plus all photos, available on my phone and they are sync'd if I make any changes.  Second would be Remember the Milk (to-do application).

Coming from WinMo, I was spoiled with Outlook sync.  Closest I've come in Android without using Google is :
- MyPhonExplorer for calendar and contacts
- Android Agenda for daily/weekly agenda widget
- MailDroid Free version (ads don't bother me) in place of stock mail program (now I get my mail)
- Astrid Tasks widget
- Speed Test to check speed and latency
- Remote RDP Lite - not bad for free
- WiFiFoFum - free wifi sniffer
- PdaNet for tethering
- Dropbox and SugarSync

Audible.com - I listen to audio books during my morning commute.  Using this app (along with the the Media Player for music) is essential to making me iTunes/iPod free.  I hate everything Apple, plus I'd rather not carry multiple devices.

GPS Status - I was frustrated with Google Navigation/Maps until I started using this app, and figured out that I need to go to Tools - Manage A-GPS State - Download.  Now my Google Navigation functions flawlessly and I was able to ditch my separate Garmin Nuvi GPS.

Google Navigation - of course the previous app mentioned took this from useless and frustrating to invaluable.  It offers more functionality than my Garmin Nuvi, with traffic data, and easy to access alternate routes.

USAA - That's my bank and it's great being able to not only check accounts, but also pay bills, and even deposit checks using my phone.

Since I got this phone I no longer need my iPod Touch or my Garmin GPS, so I'm very happy only carrying around my phone, but doing everything I did with those other two devices.