Quoting some info from Projector Central...
There are presently two types of 3D Projectors: Full HD 3D and PC 3D Ready.
Full HD 3D Projectors - A projector that is Full HD 3D compatible can use any of the 3D formats enabled in the HDMI 1.4 3D specification. These projectors are compatible with the 1080p 3D signal from a Blu-ray player, set-top box, or other HDMI 1.4 device.
PC 3D Ready Projectors - A projector that is PC 3D Ready can accept a 120Hz frame-sequential 3D signal from a computer via either NVIDIA's 3D Vision system or one of several educational software suites. These projectors are not compatible with the HDMI 1.4 3D specification used on 3D Blu-ray players and set-top boxes. This type of projecor is also referred to as "3D Ready".
Your Acer falls into that latter category which relies on 120Hz "pageflipping" 3D format. I don't know of any 3D Blu-ray players that currently support pageflipped output. That means to watch 3D Blu-ray movies on your Acer PJ you'll need to instead use a computer with a software tool like Cyberlink PowerDVD that supports pageflipping. With that solution you would use DLP Link 3D compatible glasses which are of the battery-powered, active shutter variety. They'll run about $25-$60 a pair.
By the way, DLP Link is a special built-in function of the Texas Instruments DLP chips in your projector. DLP Link sends an embedded signal to the 3D glasses between each frame that synchronizes the 3D image with the glasses. These glasses do not require a separate emitter because the sync signal is embedded in the projected image.
The only converter I found on monoprice's site is this: http://www.monoprice.com/products/product.asp?c_id=101&cp_id=10114&cs_id=1011408&p_id=8048&seq=1&format=2
That's a 2D to anaglyph 3D (red/cyan) conversion device which I'm pretty sure is not what you're looking for when you say you want to watch 3D Blu-ray movie titles.
The 3D technology landscape continues to shake itself out. I've been taking a what-and-see approach before I invest in 3D (if ever). If anyone else has more up to date info that might help burgertime please chime in. Thanks.