Seen a lot of people recently with no valve caps. Is it a new fad or just that they are unnecessary??

They are unnecessary. Their sole purpose to protect the tube from puncture while in the box or your pouch. Once tubes are mounted, toss the cap.

Odd. Except for newbies that just took their bike home from the showroom floor, I've never seen anyone else use them.

I have always used valve caps, they weigh maybe a few g and help from dust. Or have I been doing it wrong all these years???

Well imo they are necessary, they protect the valve and keep it clean, i think it's more likely to be laziness/bad practice/loss of cap.

They fall off or get lost anyway.

Possibly useful with schrader valves because grit can get lodged in the valve and ruin the seal. I find them useless on presta valves and they simply add two steps to adding air to each tire.

I remove the cap and valve nut when I install the tube and never use them again. They are both unnecessary.

I have been a cyclist for over 25 years and have NEVER used them.

What is valve caps?

the only thing I find them useful is to signal which tubes are new and have no problems.

other than that i make jewelry out of them like watches, belt buckles, and fronts.

Do you wear a bike chain bracelet? I was thinking of making one.

hum. They were too heavy I took them off.

no, i do wear a bicycle chain eye patch tho

I remove the nut as well, but keep it handy on flat changes. Holds the stem in place while you push the pump onto the valve.

I just use my thumb to hold the outside of the tire when I push the pump / co2 on.

Any pics?

Velominati Rule 60:
You are not, under any circumstances, to employ the use of the washer-nut and valve-stem cap that come with your inner-tubes or tubulars. They are only supplied to meet shipping regulations. They are useless when it comes to tubes and tires.

To each their own, But....

I find the nut very useful for inflating tires, and the cap keeps my valve from getting gunked up when riding in our daily summer rainstorms.

Caps are unnecessary but I've always left them on as they don't do any harm. If anything, they might help during a muddy ride.

totally useless on a presta valve.

What are fronts?

Valve cap is useful as it keeps dust out. If dust gets into the inner workings, it might cause the valve to leak very slowly because the little dust particles might prevent it from closing completely.

If you take them off, wheels will all-encompassinlgy be lighter tho' .

no valve caps

As a schrader tube user with a very heavy bike, I've always used them and never seen the point in not using them as the weight difference is so small (my caps have the valve puller thing on them, not that I've ever used it but it's cool to have).