I've seen a LOT of anchors hanging off the bow in boats 25-30ft (I had one on the Cal 25, and on the Crown 28). They get in the way a LOT less than you'd think - biggest problem is that if you do happen to run into something with your bow, it will scratch the hell out of it!
Being mainly single-handed, I will set up the anchor on the deck (or hanging off the roller) before I even enter the anchorage. Then when you're in the crowded anchorage, you can quickly go forward and trip the anchor off (as opposed to tripping OVER the anchor!). If there's a bit of wind, I sometimes leave the main up, motor to maybe a boatlength upwind of where I want the anchor, then go in neutral (NEVER shut the engine off till you're properly anchored!), drop the anchor and play out the rode as the wind pushes you backwards. Once the anchor sets, the boat will swing bow into the wind, and you can go back at your leisure and reverse to set the anchor properly. Once the trees stop moving, you're set!
I'd say a roller is pretty much mandatory for anchoring, even if you don't leave the anchor there.
druid