pack my boots to hike the Alps??

I definitely don't think it's worth your time an effort to carry around your hiking boots for 3 weeks. I've been to the Swiss Berner Oberland area many times and have taken several people with me on different trips...no one EVER had to have boots to do the mild and moderate walks. If you plan on strenuous hiking and climbing then yes, take them. Otherwise, no.

Kaye, unless you and yours have foot-support issues or are overweight, the answer to your question about the BO is no.

If all you plan to do is hike between villages, a good pair of walking shoes, well broken in, will be fine.

While I was in the Berner Oberland in September, not early June, my experience was that a good pair of walking shoes is fine... definitely no need for hiking boots

It's hard to say, because it all depends on the weather you get. We spent four days in Murren last August and had a lot of rain. We had brought our light hikers Merrill type and I was very glad that we did. The trails were muddy and my son, who only had cross-trainers, pretty much ruined his shoes. I'd look closely at the weather records for early June and base your decision on that. And definitely bring rain gear!! Ours was too lightweight for the weather and so we ended up having to buy expensive Swiss rain shells.

Kaye, There are never any guarantees with the weather, but I'd probably just use my normal walking shoes (well broken-in of course) as you won't be doing "extreme hiking". My last visit to that area was in September / October and the weather was beautiful and sunny so I had no problem using the one pair of shoes I was travelling with. It's difficult to offer to many suggestions, without having some idea on the specifics of your situation. For example, do you normally require a high-top boot for more ankle support when you're hiking? Depending on which hikes you'll be doing, you'll probably find that at least some of the trails will be very easy. For example, the small trail back to Mürren from the top of the Allmend-Hubel Funicular is mostly paved as I recall. Happy travels!

I would say yes, especially if you have a pair of light-weight, comfortable hikers, like Merrill or Asola, etc. My Asola hiking boots are so comfortable and supportive, that I wore them every day, even for wandering/sight-seeing around cities. I'm in very good shape (work out, bike and run regularly) and appreciated having them in the Bernese Oberland. I wore them in place of sneakers/tennis shoes. And to save space in my bag, I wore them on the plane to/from Europe. I would NOT want to pack those, as they'd take up valuable space. And even for "moderate" hiking, you'll appreciate having them. This way, if you do encounter some more challenging trails/hikes you'd like to try, you'll be all set. And even if you don't, they'll be perfect for more moderate hiking. They also have lower hikers that are same height as a sneaker (say, below the ankle) but will give you much more support/protection than a sneaker. Hope this helps. You're off to 1 of Europe's most spectacular regions, enjoy!

I think Lynne above makes an excellent point re: rain/mud. With hiking shoes, you are covered in ALL weather conditions. And even if you never encounter rain or mudd, you still have the best type of footwear for easy/moderate/difficult hikng conditions as well as for just walking around.

It's just like hiking in the Rockies – you really don't need anything more than cross-trainers for the easier-moderate trails. If it's raining, of course the trails will get muddy, but that comes with the territory. I've done moderate-more difficult hiking in and around RMNP, and cross-trainers aren't good enough for that type of terrain. But when we were hiking the easier trails across open meadows up around Mürren, cross-trainers were good enough (perfect, actually). For simple pleasure hiking, there's no way I would bring an extra pair of shoes/boots. I would adjust my hiking itinerary to something easier before I brought more stuff with me. It's not like you're going out on a 10th Mountain Division military exercise. :)

Kaye, I managed an outdoor retailer for the better part of 10 years, so I used to field this question all of the time. As a frequent traveller to Europe, I would say that you will be fine on moderate hikes with walking shoes/sneakers. I can't justify the space and weight of the hikers for just a few days of light hiking. When I go to Europe, I wear trail running shoes (beefier running shoes) and I can do anything with them. Yes, if it's raining or muddy, you will get muddy, but your likely to get pretty muddy with hiking boots on also.
Renting is a definite no-no, since the break in period is too short, and they're likely broken in to the shape of someone elses foot.