Gadgets, widgets and snippets:
Yahoo Pipes – Features:
Import RSS feed . Provide an RSS feed URL for input, or specify a web service – such as Flickr – from which to retrieve an RSS data stream.
Get user input . To build robust Pipes, you need a way of letting end users supply information: search terms, URLs, dates, quantities, etc.
Generate URLs . If you want to marry Pipes with outside services, you will sometimes need ways to generate web service URLs on the fly, using user-supplied information.
Aggregate multiple feeds . Combine multiple RSS feeds. How multiple feeds are combined is dependent on which other modules are used (sorting, filtering, etc.)
Sort by value . Given a stream of RSS data/ content items (whether from a single source or mashed together), sort the stream by some field value. This could be by item date (usually the same as publishing date), title, category, etc. What you use depends on both what actual RSS/XML data you are importing as well as your specific functional need.
Pass filtering . Pass filtering just means that given your RSS stream, you want to specify which data items should be allowed to pass through to the next step. For example, if you are mashing together several blog feeds, you might “pass” items based on date, author, or a search string (e.g., posts about “Corvette” cars). Or you can filter out items by eliminating duplicate titles or URLs.
Transforming data fields . Sometimes you want to take the text content of an RSS stream and alter it using a set of rules. You might add or eliminate data fields, replace occurrences of a word or phrase, count items satisfying a criteria, geocode the data to produce a map, etc. There is no one single Pipes module that you use to transform data; there are many transform/ operator modules, each with a specific functionality.
Mathematical operations . Yahoo Pipes offers some very basic math functionality that can be combined with either numeric user input or suitable modules that produce a numeric value.
Plug-n-play of custom web services . The Yahoo Pipes interface is integrated with several external web services. However, a few months back, they introduced a module by which you can plug in your own custom web service.
Looping . Looping lets you repeatedly apply a block of Pipes modules over each item in an RSS stream. In fact, you can build a block of modules into a Pipe, name it, then access it from a loop in yet another Pipe.
Output results . The output of a Yahoo Pipe is a new RSS feed by default, though you can produce geocoded Yahoo Maps as well.
Sprout
From sproubuilder website:
Whether you’re a beginner or a pro, Sprout has a range of features that will allow you to quickly and easily build, publish and manage rich media Web content including widgets, minisites, banners, mashups and more.
Timeline
Timeline is a DHTML-based AJAXy widget for visualizing time-based events.
Popurls
A popular site that lets you get a bird’s eye view of several popular sites.
Timer
Timer is a Twitter bot that helps you set an alarm for things you need to remember