Quite a few of newer phones, including my Samsung, have the ability to charge wireless through some electrical gobbledygook. This together with the ability to transfer files via wireless, or email, can make the USB port redundant. But I don't think this wireless charging ability comes with 'inexpensive' phones.

Just another thought,

Before moving to my first iphone (5) with the new power connector I used blackberries. Having a dedicated, secure dock or place to charge your phone goes a long way to avoiding problems with your microusb ports as they tend to be a bit fragile.

I also always stuck some Prestik over my charging and earphone ports to prevent dirt and water incursion. 

But again, I'm the guy who bolts the family laptop to the table believing that a laptop is a portable computer and not a computer to be operated on a lap.

So take my opinions from whence it came.

Magnetic charging cables might be a solution for those wishing to avoid corrosion on their phones/tablets charging ports.  I've used them, mostly successfully, on my sons phones in order to avoid damage to the charging ports from the cords being pulled in inappropriate directions.  There is a small stub that stays permanently in the charging port and the special charging cord that magnetically attaches itself to this nub along with some small pins.  They seem to last about 6 months to a year before they start to become erratic for a reason I've been unable to diagnose.  I've only used the cheapies off e-bay, so maybe that is part of the problem.  If you fill the charge port with dielectric grease before you plug the tiny stub into the phone I would expect the port to last a very long time.  It's easy to revert back to a regular charge cord should things not work out.

Although tiny, the magnets in the cord are strong enough to effect our binnacle compass if the charge cord is closer than 4" (10cm) from the compass and in line with the compass card.  Something to think about if you have a tablet mounted on a binnacle and are charging it, or some other situation with a device close to a compass.

Here's a good write-up of the use of grease in electrical connections.

According to the writer, dielectric silicone comes out best.

"In regular low voltage multiple-pin circuit connectors, such as automotive applications, flooding with a proper insulating grease of low-viscosity dielectric grease is perfectly acceptable unless a manufacturer recommends against it. The grease should have good stability and not contain metals in any form, and be specifically designed for use as a dielectric grease. This generally is a silicone dielectric grease, although some Teflon based greases are acceptable."

David Tyler wrote:

Nicolaas wrote:

If you are having corrosion problems I would recommend regularly 'greasing' all your marine electrical outlets (12v, 5vUSB, 5vmicroUSB, etc) with conductive silicon grease maybe it will work on your phone port too.

Can you recommend a brand, Nicolaas? I'm aware of silicon greases with thermal conductivity, but not electrical conductivity. That would be a useful thing to have aboard.

I'm not convinced you actualy want an electrically conductive lubricant in your microUSB connector... 

I have heard good things said of Contralube 770, which is sold as an electrical contact grease. Not cheap!