There are a number of graphics applications available to Ubuntu users, from simple to complex. We are sure that you will find one to suit your needs.
Some applications come with the default installation of Ubuntu and even more are available in the repositories or elsewhere in the form of deb packages or tar balls.
Applications installed by default
Evince - Document Viewer for PDF and PostScript files
Eye of GNOME - Image Viewer
OpenOffice.org Draw - Images and diagrams creation and manipulation
XSane - Scanner application
Shotwell Photo Manager - Photo manager
Applications in the repositories
Agave - Color schemer
Blender - 3-D Modelling
Dia - Diagrams
digiKam - A KDE friendly Photo Management Application
feh - An image viewer at heart, though it does other cool stuff
F-Spot - Photo Library
Gcolor2 - Simple color picker
The GIMP - Advanced image creation and manipulation
GNUpaint - Simple painting program
ImageMagick - Graphics editing
Inkscape - Vector graphics
Istanbul - Desktop Session Video Recorder
MeMaker - Creating Avatars
Mirage - A fast and simple image viewer
Tux Paint - Award-winning painting program for children
Xara Xtreme - Vector-based illustration program
Applications available elsewhere
Oqapy - Photographic workflow software
jBrout - JPEG photo management software
Picasa - Photo management with intermediate-level editing features
Tonido Photos - A peer-to-peer photo sharing and organizing application
GNOME Art - Community of artists based around the GNOME desktop.
The Open Clipart Library - a collection of Free clipart.
Flickr Creative Commons - Creative Commons-licensed works on Flickr.
Tango Desktop Project - Project offering guidelines on styling icons and graphics for open-source software.
Licensing your Work
Free Software Foundation License List - note: 'There is literally no specific freedom that all Creative Commons licenses grant'
Creative Commons - Non-profit organisation offering flexible copyright licenses for creative works