Accessories for the new Canon DSLR camera

This list has items specific to the Canon 650D/T4i, but many will work with other cameras

Accessory Description Price (free shipping)
LP-E8 battery Canon LP-E8 Compatible 7.4V 1200mAh Battery Pack for Canon 550D/T2i 600D/T3i 650D/T4i
You can never have enough batteries
UV camera filter 67mm PRO1-D DMC Ultra-Thin Multi-Coated UV Camera Filter - Black (67mm) $13.70
CPL Polarizer filter 67mm CPL Polarizer Lens Filter (67mm) $9.70
Screen protector Canon 650/T4i FOTGA Optical Glass LCD Screen Protector for Canon 650D/T4i $5.20
Lens Cap Camera Lens Cover with Center Pinch (67mm)
You will be able to remove the cap with the hood attached to the lens.
Lens pen Lens Cleaning Pen for Digital Cameras $2.94
Air blower for lenses Large Air Blower Duster $5.08
microfiber cloths Microfiber Screen and Glass Cleaning Cloths (Random Colors / 6-Pack) $1.90
Camera remote control Wireless IR Remote Control for Sony/Canon/Nikon/Olympus/Pentax $3.60
Flash diffuser Universal Portable Flash Diffuser Soft Cover for SLR Camera $4.50
Flush gun stand Flash Gun Stand for Canon 580EXII/580EX or anything with hot shoe,
attaches to tripod with 1/4" metal socket
Shoulder strap for DSLR camera Universal Neoprene Shoulder Strap for SLR/DSLR Cameras
No camera brand screaming "steal me"
P-Type holder P-Type Filter Holder for SLR Camera (52mm) $5.36
P-Type holder P-Type Filter Holder for SLR Camera (58mm) $5.33
P-Type holder P-Type Filter Holder for SLR Camera (67mm) $5.27
P-Type filter ND4 P-Type Gradual Grey Color ND4 Filter for DSLR $4.20
P-Type filter ND8 P-Type Graduated Gradual Grey ND8 Lens Filters Set (2-Piece Pack) $8.30
Bettery grip canon 550D 600D 650D T2i T3i T4i MEIKE 1.5" LCD Multi-Power Battery Timer Grip w/ Remote Control for Canon 550D/T2i 600D/T3i 650D/T4i
With this grip you use two LP-E8 batteries or 6 AA batteries.
What setts this grip apart from most other grips is the built in timer mode,
you can take time laps pictures with it.
Video light LED T6-A T6-A Rechargeable 16W 5600 / 3200K 6-LED White Light Video Lamp for Camcorder / Camera $74.70
Photo reflector 5-in-1 43"/109cm Multi Photo Light Collapsible Reflector $22.00
Clamp for tripod Universal Clamp Mount for Tripods (Holds up to 3.8cm Thick Objects) $2.70
GPS receiver data logger HOLUX M-1000C Rechargeable Bluetooth Car GPS Receiver with Data Logger Travel Recorder
You can geotag your pictures with this GPS logger, also useful for checking the distance of a walk.
Kenko Auto Extension Tube Set for Canon EOS Kenko DG Auto Extension Tube Set for the Canon EOS AF Mount.
This allows you to focus much closer then what the lens would permit
Varies, cheapest on eBay about ~$150

You can find many more accessories for digital cameras here.