I carry mine in a red-with-white-spots Cath Kidston book bag one of my clients gave me.
While it's not padded, the advantages are that it doesn't scream "valauble hardware" when it's tucked under my arm and I just really, really love it!
I usually pop a poly bag over the top end of my laptop, just in case it rains, and it's maybe not everyone's ideal solution but it works for me!
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