I guess, in this day and age, we can't be too careful when we are out and about.  Well, now there is an app for that.  It's called "Spraytect" and it's an attachment for your phone.  Take a look at this video clip to see how this works.  This just might be something a little easier to handle than an actual aerosol can by itself.  Most people are holding on pretty tightly to their phones these days, so now you can be ready.