Question: Is it scientifically possible to briefly walk on the moon bare footed?

What possible side effects could there be?

Are these side effects mild enough to make it worth it?

Answer: 
There are 3 main threats you'd have to account for: 

1. Vacuum. This is discussed in the questions @Forgemonkey linked to. Conclusion: brief exposure of the feet only is survivable.
2. Temperature. Surface temperatures on the Moon swing between + 120 and - 150 °C, so you'd have to pick your spot carefully to have a survivable temperature.
3. Cuts and abrasion. Lunar [regolith](http://www.airspacemag.com/space/stronger-than-dirt-8944228/?no-ist) is [very sharp](http://www.universetoday.com/96208/the-moon-is-toxic/). It'd be like walking across glass shards. On Earth, dust and sand are subject to erosion from wind and water, which tends to make everything smooth. On the Moon these forces are absent, so e.g. the debris from a meteorite impact all keeps its sharp edges indefinitely.

All in all, not a pleasant experience, I'd think.
For the record here's a direct quote, from the [same article](http://www.universetoday.com/96208/the-moon-is-toxic/) Hobbes discovered:

> 
> “The dust was so abrasive that it actually wore through three layers
>  of Kevlar-like material on Jack [Schmitt’s] boot.”
> 
> 
> 

– Professor Larry Taylor, Director of the Planetary Geosciences Institute, University of Tennessee (2008)

I observe that the "ground" on Earth is soil, which is an organic substance and (even in the driest places) **very wet and springy**. What we think of as "very dry, hard" earth (in the "outback") is nothing compared to, say, imagine a try with an inch of tiny and large metal filings. I suggest the issue of what the lunar "soil" feels like is somewhat unknown. We do know it wore-through three layers of kevlar, even in the low gravity, in about 20 hours.