This one, I just can’t believe nobody’s done it yet.
I want a backpack to carry my camera gear in. This includes a tripod. My tripod (I have the purple) is only 15.5″ wide when collapsed. What I don’t understand is why nobody appears to make a backpack with adjustable gear straps across the bottom where a tripod could be strapped in. This would also be good for yoga mats, and I spent some time looking for yoga mat backpacks with this kind of feature, but to no avail. The only bags I can find that have anything like this are the Rickshaw messenger bags. Even Timbuk2’s messenger redesign has eliminated the bottom-of-the-bag straps. But I wouldn’t get a messenger anyway; Alex and I went on a photo shoot last weekend with all my gear in a tote and it gave me a headache. I’m either planning to buy a fun Zuca Sport bag (which has wheels) or buying some webbing and buckles to sew straps onto the Pacsafe backpack we use for travel (and you all know how that sort of thing tends to turn out).
Meanwhile, here is a photo from that shoot on Sunday.
The US Picks 
Most backpacks for overnight hikers have slings on the bottom for carrying sleeping bags or mattress pads. I don’t know if they can be cinched tight enough for a tripod, but you could go to a store like REI and check them out.
Well, that’s the thing; I didn’t want some massive frame backpack. We only need to carry my handbag, the tripod, two point & shoots, one DSLR, a Surface and a little bag full of accessories like the card reader, chargers, etc. I *can* get this all into my tote bag (except CP’s DSLR) but it is a bear to carry, as mentioned. I wanted something like a day pack with the external sleeping bag straps. I do see one from Osprey that might work – the “Sirrus 24” – which is not overwhelming, has the straps, but actually does have an internal frame, so that might make it problematic. Will keep y’all posted.