Thanks for the insight MarthaK!
Let me make sure I understand... Some of yours have replaceable bulbs while others do not? That's good to know because I would have assumed that they were all replaceable. I'll need to check the ones I was looking at the other day. I definitely want to be able to replace bulbs.
The price of the ones I was looking at (at Lowe's) were actually about $0.50 less than the same 25ft/25-light strings of standard lights at WalMart. That's another reason I was so intrigued by these.