I'll add my vote for Things! I was designing my own app to do this then Things came out. If you've ever been inspired by GTD - Getting Things Done, by David Allen, Things is an indispensable app, My third most used app next to Mail and Safari. It also has great support for syncing with the iPhone so you can take your lists on the road and store your tasks or ideas wherever you are.
Mailplane is great, especially if you have multiple gmail and google mail accounts.
Things' lack of reliable, convenient syncing killed it for me. OmniFocus, while not as sexy and certainly more complicated than Things, has rock solid syncing to your iPhone or Mac via MobileMe or any other webdav server you choose. And its robust configurability means you can set up a very Things-like workflow if that's your bag. And the iPhone version is sweet!
If you want to have todos available in more than one place, Things will bring you nothing but tears.
Cornerstone is a good alternative SVN client. Cyberduck is a pretty good general purpose SFTP/FTP/S3/etc client. I like billings better than on the job personally.
I find cornerstone a lot better than versions. Although moved to Git now and feel like an idiot for buying a subversion client!! :P
1. Things - Awesome task management - http://www.culturedcode.com/
2. Mailplane - If you use GMail this is a must. - http://mailplaneapp.com/
3. AppZapper - Remove everything about an app - http://www.appzapper.com/
4. LittleSnitch - Filters and prompts on outbound ip connections - http://www.obdev.at/products/littlesnitch/index.html
5. Undercover - Stolen Laptop Recovery app - http://www.orbicule.com/undercover/
6. Fugu - SCP/SFTP App - http://rsug.itd.umich.edu/software/fugu/
7. On The Job - Time and Expense Tracking - http://stuntsoftware.com/OnTheJob/
8. Versions - Awesome SVN client - http://versionsapp.com/