Ajax Animated Icon Generators
Sure there are a few standard icons that you can use for your waiting dialogues in your apps, but here a list of new and old ones… just for a bit of variety:

CSSLoad.net (css)
http://cssload.net/

Canvas Loader (javascript)
http://heartcode.robertpataki.com/canvasloader/

Chimply (animated gif)
http://www.chimply.com/Generator

LoadingGif.com (animated gif)
http://loadinggif.com/

Neteye activity Indicator (javascript)
http://neteye.github.com/activity-indicator.html

spin.js (javascript)
http://fgnass.github.com/spin.js/

Preloaders.net (animated gif and/or javascript and css sprites)
http://preloaders.net/
Developer Cheat Sheets
Web Development Cheat Sheets
HTML cheat sheet:
http://floele.flyspray.org/htmlcheatsheet.pdf
CSS cheat sheet:
http://www.addedbytes.com/cheat-sheets/css-cheat-sheet/
PHP cheat sheet:
http://www.addedbytes.com/cheat-sheets/php-cheat-sheet/
Ruby on Rails cheat sheet:
http://www.addedbytes.com/cheat-sheets/ruby-on-rails-cheat-sheet/
MySQL cheat sheet:
http://www.addedbytes.com/cheat-sheets/mysql-cheat-sheet/
Regular Expressions cheat sheet:
http://www.addedbytes.com/cheat-sheets/regular-expressions-cheat-sheet/
Search Engine Optimisation (SEO) cheat sheet:
http://www.seomoz.org/blog/the-web-developers-seo-cheat-sheet
JavaScript & JavaScript Framework Cheat Sheets
JavaScript cheat sheet:
http://www.addedbytes.com/cheat-sheets/javascript-cheat-sheet/
jQuery cheat sheet:
http://www.gscottolson.com/weblog/2008/01/11/jquery-cheat-sheet/
jQueryUI Icon Reference cheat sheet:
http://www.petefreitag.com/cheatsheets/jqueryui-icons/
MooTools cheat sheet:
http://mediavrog.net/blog/2008/06/11/mootools/mootools-12-cheat-sheet/
Prototype cheat sheet:
http://thinkweb2.com/projects/prototype/prototype-1602-cheat-sheet/
Scriptaculous cheat sheet:
http://www.slash7.com/articles/2006/04/22/scriptaculous-cheat-sheet-1
extJs cheat sheet:
http://huseyint.com/projeler/extjs-cheat-sheets/
YUI cheat sheet:
http://developer.yahoo.com/yui/#cheatsheets
Also…
Wordpress Help Sheet
http://www.quicklycode.com/wp-content/files/wordpress_helpsheet.jpg
JavaScript, A few nice JavaScript add-on library’s
I’ve recently discovered quite a plethora of add-on libraries for JavaScript that are compatible with several other libraries (such as jQuery). Here are a couple of neat little additions to your ever-growing library of JavaScript tools and helpers.
Underscore
Underscore is a utility-belt library for JavaScript that provides a lot of the functional programming support that you would expect in Prototype.js (or Ruby), but without extending any of the built-in JavaScript objects. It’s the tie to go along with jQuery’s tux.
Underscore provides 60-odd functions that support both the usual functional suspects: map, select, invoke — as well as more specialized helpers: function binding, javascript templating, deep equality testing, and so on. It delegates to built-in functions, if present, so modern browsers will use the native implementations of forEach, map, reduce, filter, every, some and indexOf.
Backbone
Backbone supplies structure to JavaScript-heavy applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing application over a RESTful JSON interface
Backbone’s only hard dependency is Underscore.js.
For RESTful persistence, history support via Backbone.Router and DOM manipulation with Backbone.View, include json2.js, and either jQuery ( > 1.4.2) or Zepto.
Knockout
knockout.js helps you simplify dynamic JavaScript UIs using the Model-View-ViewModel (MVVM) pattern.
By encapsulating data and behavior into a view model, you get a clean, extensible foundation on which to build sophisticated UIs without getting lost in a tangle of event handlers and manual DOM updates.
Micro-frameworks are definitely the pocketknives of the JavaScript library world: short, sweet, to the point. And at 5k and under, micro-frameworks are very very portable. A micro-framework does one thing and one thing only — and does it well. No cruft, no featuritis, no feature creep, no excess anywhere.
Microjs.com helps you discover the most compact-but-powerful microframeworks, and makes it easy for you to pick one that’ll work for you.
jQuery Mobile
jQuery mobile framework takes the “write less, do more” mantra to the next level: Instead of writing unique apps for each mobile device or OS, the jQuery mobile framework will allow you to design a single highly branded and customized web application that will work on all popular smartphone and tablet platforms.
LINK: http://jquerymobile.com/
Detect Mobile Browser
Created by Chad Smith, the Detect Mobile Browser code is open source, available in 15 languages (or as plugins), is supported by a redirect service via which you can setup mobile redirec links for your own programs.
Link: Detect Mobile Browser - Open source mobile phone detection