I don´t need a full fledged framework like Sencha or jQuery mobile, just the ability to detect gestures such as swype or pinch to optimize some parts of my site for touch devices.
I have never worked with touch events so I dont really know where to start. Is there a light framework or jQuery plugin for this?
You can check those out: Hammer.js, which you can run standalone or as a jQuery plugin, QuoJS, which is a microlibrary it should work fine alongside jQuery. If you are planning to use jQuery UI then touchpunch should do the job!