There are many services on the web that offer you photoshopesque abilities and features. They range from complicated and powerful to simple and lightweight. My favorite is Splashup.com. It’s a pretty good mashup of usability and features.

Splashup runs in all browsers, integrates seamlessly with photosharing sites, and even has its own file format so you can save your work in progress.

It offers all of the basic features I’m used to plus some of the ones I would not expect online. The ability to use layers and filter effects makes it possible to actually create decent looking designs online. Splashup offers a very smooth and useable interface, But honestly, most web 2.0 apps do. It’s completly free and no registration is required. However, if your looking to save work onine the do give you the option to create an account.