4K HD Wallpaper: Inside Coconut
New 4K picture from Chris that is available under CC By-Sa license that can be downloaded from here optimized for fit on desktop backgrounds and homescreen phones.
Widescreen (Desktop / Macbook): 2560x1600 (fits on: 1920x1200, 1440x900, 1280x800)
High Definition HD 1080p: 1920x1080 (fits on: 1600x900, 1366x768, 1280x720)
Samsung Galaxy Tab & iPad: 2048x1536 (compatible with almost all tablets)
HTC, Samsung Galaxy & iPhone: 1080x1920 (compatible with many smartphones)