I had been using Circus Ponies NoteBook for years when I made the switch. I transferred over 5GB of data from NoteBook's painfully slow file into Together. It took a long time but it was well worth it. Together is a very well written application with a top notch user interface and the developer is quick to respond to bugs and questions. Highly recommended.

I love it! Much better thatn Yojimbo and Devonthink, I stiil has to see with usage how it handles large databases, but so far so good, beautiful and easy to use, and the reason to buy, a committed developer, not the type of get the money and run. I hope to see this app growing, because it could be one must.

@groxx The new 2.0 version was completely rewritten and addresses the missing features you mentioned. I have ensured KIT 1.x is stable on Tiger and Leopard with no known problems. While I'm not adding features to the old version, I still support it in that way. Send me crash logs if you're having problems.

Still have the previous version, as this one is 10.5 only.
As to the previous version, I've tried to get into it a few times... but the GLARING inadequacies prevent me from using it. Two biggies: doesn't search spotlight comments (WHY?!), and doesn't allow nesting groups. So the "groups" aren't really groups... just flat folders.

Yes, it lets you see your files in one location. Yes, it gives you categorization options (though severely limited). Yes, it can open most kinds of files.
No, it can't change HOW you open your files (what? no MPlayer support? ick, no). No, it can't nest groups. Yes, it crashes often.
No, it's not worth the money. Barely worth ANY money, actually. I wouldn't use it if it were free.

Unless the newest version has some truly massive changes in both the underlying design and the user interface, my opinion is extremely unlikely to change.

Needs .Mac syncing to be useful for me.

The 2.0 version of (Keep It) Together is a major improvement. It combines some new features Now using QuickLook-technology it shows the content of files in a very fast and convenient way. There is also a dropper (which resembles some other organizers, which used this feature earlier. I think Together is the #1 app for browsing a huge amount of files. In the difficult field of organizing information, there are some features which are not implemented and would be able to make this app complete.
What's still missing?
1. The ability to tell the application to auto-write tags and labels into the spotlight-comments (like e.g. nifty box or punakea). That would be nice for people who switch between computers or working in groups on projects or for people who decide in a year to leave Together. If you do so, all your organizing tags and labels are gone, they are in no way attached to the files but only stored in the app's database.
2. Folders, groups and smart groups. Together now supports folders and folders packed in folders. That helps holding the list of items which belong to a special case (etc) short. But it doesn't support groups or smart groups packed into folders. I don't understand why. I think almost all people want to have at last a folder called archive which holds some goups (e.g. customer-groups or project-groups) and all files which are tagged "archive". It's hard to scroll through 300 groups and smart groups on an macbook. With the support of folders holding groups and smartgroups one can reduce this to 10 folders each containing a bunch of groups and smart groups.
3. Here's a "sugar on top"-suggestion: it would be nice when the files could be previewed in full screen mode and the comments field would be a floating field (watch the app "Papers" to see what i mean), that would be a nice feature to add comments and notes to long pdf-files).
So here is the summary: Together is a great app for conveniently storing tons of information and for browsing through it. It has nice labeling and tagging features. The organizing features are not fully sufficient, there are some lacks which limit the freedom of the user in organizing the stuff the way he likes, another problem is that you cannot switch to another application without loosing your tags. (I write this last point because i had the problem after using an early version of k.i.t. which collapsed orgainizing 800 mb of pdfs and rtf-files).

I just bought this last night to keep a central repository for items related to my next vacation. I wish it had spotlight integration but other than that I like it.

With the latest release it became very useful and "stable" software. Now it doesn't lose documents when it crashes. Crashes seems to happen due to corrupt rtf and pdf files.

To compare it with devon: I like it more than devon because you can open and change your files with your favourite programs (i don't like editing long texts in the devon workspace).

Alas: there are two more changes which i would like to see in further versions:
a) hierarchical folders: i have too much stuff to get it organized in a plain way.
b) there some filetypes i would like to see added: mainliy Omnioutliner

What's the difference with DEVONthink?
The only difference I've found is the option to keep original format.
In DEVONthink, all text files change into RTF file, even Word file or Nisus file. Is there anything else?

Love it. Is it perfect, probably not. But what is. I've never experienced any of the crashes people here have mentioned. And like another person mentioned, KIT is like Notational Velocity on Steroids, and I love Notational Velocity.

But in the end, I use KIT and would recommend it to anybody.