I find the moses basket and sling very useful for naps. I can move the basket to whatever room I'm in so baby isn't far, or I can wear her (which allows me to keep in better touch with her needs.)
She shares our bed, too, but doesn't sleep there alone. (It's too high!) When I do lay her on the bed (while I'm getting dressed or such), I place a small buckwheat pillow on either side of her, in line with her armpits, so she can't go far.
I like the idea of the Family Sleeper (familysleeper.com) for when she's able to crawl, though.
My little kids would often take naps or maybe be put on the adult bed after falling asleep somewhere else. We would have a baby monitor on if we were in the other room and would always check in frequently, but there was the big fear that I would hear my baby and before I could get there...boom....baby hitting the floor.
This tip really worked for us, and our babies caught on faster that I thought they would, because I don't think they like falling off the bed either. Ouch!
Once your baby starts to crawl and be mobile is the time when they're really a falling risk. Well, by teaching them how to scoot off the bed backwards and safety slide to the floor we were able to stop plenty of falls. You can add soft pillows around the edge of the bed in case they slide too hard or do fall. Teaching them to grab the blankets and hold on as they scoot backwards helps.
Of course staying nearby and checking in very frequently is always recommended when leaving baby on an adult bed.
Things to remember are
Babies can wake quietly and be getting into all sorts of trouble without you knowing
Babies can suffocate or choke very quickly..remember to check babies often when left unattended
You can learn to use a baby carrier for baby and carry baby while they sleep
You can let baby nap in the same room as you in a moses basket or sleep pad.
