Cloud Aggregators

I discovered most of these via Gary Price's Best Betas presentation at Internet Librarian. As web apps are exploding and replacing desktop ones, I foresee that services that enable cooperation and aggregation amongst web services will be increasingly in demand. Here's my first taste.

Hojoki

Updated: 3/11/12

I just discovered Hojoki so I thought I would update this post & include it. Hojoki isn't terribly different from the other cloud aggregators here; you can add accounts, from Google Docs to Mendeley (which is a cool bonus for researchers who use that service) to Github, and all updates appear in one place. You can create "Projects" which function as folders and can share folders with people. Updates from any service appear rapidly in Hojoki's equivalent of a timeline, making it a great real-time collaboration tool. Right now, the list of services supported is moderate but interesting. It's particularly cool to see Github & Beanstalk support, meaning that this could make for a better code-collaboration tool than the others on this list. However, lack of FTP/WebDav support makes it more limited than, say, Otixo, which is still what I would recommend as a singular desktop for all your files in disparate cloud applications.

Greplin

Named after the Unix grep command that searches for regular expressions, Greplin is less of an aggregator than a personalized search engine. Not personalized in the way that Google, Bing, and some (but not all...see Blekko and DuckDuckGo, which I believe don't alter results based on personal information) other search engines are these days, but in that you give it access to accounts like Gmail, Facebook, Twitter and it indexes the results. The list of services you can index is fairly large. The user interface is minimalist and slick. Overall, it looks well-done and has the largest chance of making it into my everyday Internet usage of anything on this list.
My only gripe with the service thus far is how it orders search results. First comes Mail, then Events, then People, then Files, and finally Streams (Twitter/Facebook accounts...not much different from People, actually). That's almost precisely the opposite order I'd like to see. When I imagine the utility of something like Greplin, there are two basic use cases: "Damn, what was the cool link I saw somewhere but didn't save?" and "Shoot, where is that document I wrote, in Google Docs or Dropbox?" Neither of those use cases involve my Gmail contacts or Calendar events, yet those are the search results that rise to the top to the detriment of more useful items. I figure Greplin is still young and custom result ordering is probably on the way, so I'm not too concerned. But it does point to perhaps a fundamental misconception of what the service is for.

Otixo

Combines my Dropbox and Google Docs in the same place, a great answer for use case #2 above. This service has, by far, the most limited set of third-party sites it can pull content from, but it might be able to focus in on a single task better because of that. A service that tries to be everything to everyone usually becomes bloated and fails (cough...Facebook...cough). You can also add FTP or WebDav sources, which makes it pretty customizable. I could see this becoming a single source for my scattered web design projects.

Primadesk

This is the only service which I ruled out pretty quickly. It may just be further in beta than the others, but the overall design struck me as clunky and there were signs that the service was very buggy. For one thing, when I went to remove my account, I received an unfiltered error message displaying a Java call stack. I'm nowhere near hacker enough to exploit this but still it sounds an alarm bell in my head when a service that can access my Google, Facebook, and Dropbox accounts gives me a peak at its server-side code. It is one thing to be in beta and another to expose users to error messages. It is even worse when I contact your tech support (whose email address was not easy to locate) and receive no reply.
The list of services you can combine is pretty great, though; around the same size as Greplin. I didn't see any WebDav or FTP support like Otixo, though.

Voyurl

I asked for a beta invite from them and haven't heard back. It sounds more akin to Greplin than Otixo and Primadesk, as in it aims to be a personalized search engine rather than a unified cloud file system. The primary things that intrigue me are the browser plugin (judging from the screenshot it's a Chrome plugin, which is great) and the personal analytics. I'm a data-minded person and I use a lot of social sites, such as Goodreads and Last.fm, simply as repositories of information about myself.