"File Upload widget with multiple file selection, drag&drop support, progress bars and preview images for jQuery.
Supports cross-domain, chunked and resumable file uploads and client-side image resizing.
Works with any server-side platform (PHP, Python, Ruby on Rails, Java, Node.js, Go etc.) that supports standard HTML form file uploads.
"

jQuery drag & drop fallback strategy for mobile touchscreen devices: tap-to-lift => tap-to-drop.
Only partially convinced; weird experience.
Just tested on IOS browser, Android 2.2 and 2.3 browser and Firefox beta for Android, works just fine.

A free plugin to sort html tables with ajax in jquery (the plugin comes with a whole jquery framework)

rounded corners in jquery. Found via Bogdan

super usable "drag and drop" captcha. Via blog.aysoon.com

Via Daniel Huf

Flash => HTML5 converter. More or less functionnal on the iPhone and iPad
via @ldumont

HTML5/CSS/JS Framework for IOS and Android.
via Pascal Escarment