[Macworld]

Post your comments for Your desert island app here

[holzwege]

Love BBEdit, and I use it. My 3rd party app of choice is Mathematica, though.
I'm asuming, of course, that Xcode -- an Apple App -- is already installed. ;-)
geo3rge

[pwrbkdude]

I think I'd want a CAD program so that I can engineer a boat to get off said island...

[NStar]

Skype so I could call out for a pizza or Search and Rescue.
Seriously, it would have to be 1Password. I'd go insane without it.

[unixman]

Evernote. Hands down, this is the most useful information manager that I've ever found, and it SYNCs to all my machines and iPhone! Text, HTML, pictures, voice notes, it has it all.

[RobLewis]

Just ONE app? As much as I'm uncomfortable saying it (and I can hear the hoots already), it might be clunky old Microsoft Word. You gotta admit, it does a lot for one app. It's not my first choice for anything. But it's my second or third choice for several things.

[techwild2008]

My desert island app? Word and Excel are tied at #1. They're just that indispensable for me.

[jplpagan]

What I find kind of amazing is how little need I'd have for a 3rd party app. My first thought was that I'd need games, but I could play those online. Then I was thinking of other things, like communication apps and the like, but with iChat I'd be covered. I could research using the web. Keep a blog with iWeb or just a browser-based service. I could use PhotoBooth for shooting pics. iTunes to dl movies and music. I could write with just textedit, or better yet, Pages if I can have iWork (it's not 3rd party).
I'm tempted to say Adium or NetNewsWire, but i wouldn't NEED those. I could do that stuff without them. Even an FTP client isn't necessary if I just want to send large files from one place to another.
The one app I'd love to have, I guess, is InDesign. Keep myself entertained designing missives to people. The whole Adobe CS4 Suite would be nice, but that might stretch the boundaries of your challenge.
Though I suppose if there were a location-triangulating 3rd party app, I'd go with that. ;)

[kennethben]

I use MS Word more than any other, but any word processing app would likely do as well. My greatest need is to keep my life organized, and Things (from Cultured Code) has done that better than anything, especially with its iPhone syncing capability (which is better than any other app I've tried).

[scotty321]

OmniOutliner Pro -- greatest organization program ever!
Although it doesn't sync to anything right now... hmm, hopefully that will change in a future version.

[andrewburke]

I would have to say Butler for the gazillion ways I could assign shortcut keys for launching apps, inserting text, controlling iTunes etc. My mouse doesn’t track well on sand.

[spinoza2]

Even though I use my Mac several hours a day, I also have to admit I pretty much stick to Apple apps. By far I use iWeb and Pages the most; between the two, Safari, iTunes, and Mail, about 75% of my app usage is covered. More occasionally I use BannerZest Pro (all the apps from Aquafadas are terrifically creative), Adobe's Digital Editions (a terrible app, like most of Adobe's stuff, but I have a lot of ebooks), Scrivener is useful, and of course Onyx. Mindjet Manager is good, and I like Ultralingua's dictionaries.

[maremare]

Xcode. Then I can use all that time alone to make some new applications. And have a lot of fun doing it. With Wifi I can look up code examples if I'm stuck, or download PDF books to learn new things.