There's no doubt that the R12 series manifold and air intake boot clamps are a "different" design to any I have encountered in prior bikes.
Several have mention difficulty removing them and although shreddr has successfully used channel locks, I wanted to find something more appropriate, because, I'm just that way. The clamps are not unlike CV boot clamps on modern automobiles. I started researching CV boot clamp pliers but most were very large-too large for this application. Then I came across this pair:
They are Balkamp CV boot pliers, part # BK 7769238 and are available at NAPA Auto Parts stores. I paid $8.07 plus tax. Here's the link:
Store Locator | NAPA Online
There are four "tabs" on these clamps, two to the top direction and two to the bottom direction in this right cylinder view.
Looking at the right side manifold, you take the CV boot clamp pliers and gently squeeze the top two tabs together. The clamp separates without a lot of force.
To re-connect the clamp, squeeze the bottom two tabs together. They'll connect with a light "snap" sound.
I removed and re-connected the clamp a few times easily - these pliers, IMO, are the answer.
They receive my nomination for 2011 Tool Find of the Year.