You might have caught this as it started yesterday. Canon's offering instant rebates on a variety of Lenses (and flashes), but if you go direct to Canon's website there's tax and hefty shipping fees involved. You can find the same rebate information over at B&H and for some this means saving big on sales tax. Nothing overly exciting, and it extends throughout September 3rd. Current Canon Lens and Flash rebate information can be found following the link (click here).
Canon Lens and Flash Rebates