I should mention that I've seen a few cases for the iPhone 4 and I think Apple's "bumper" is the best. It's unobtrusive, it's consistent with the style of the phone, and it feels like I'm holding a phone and not a phone wrapped in something.

I didn't get the bumper originally but did after a couple of weeks — not at all because of any antenna issues, but to keep the phone from sliding off my desk with the slightest accidental nudge.

Benefits of the bumper:

• The rubber edges provided a nice amount of grip so that the phone stayed in place.
• The phone was lifted slightly off the table, so if there was a bit of grit on the table the glass on the phone wouldn't get scratched.
• I could lay the phone down on its face without fear of scratching the front; this gave me slightly more privacy in the event that I got a sensitive text message.

Drawbacks:

• The bumper doesn't fit in the dock.
• The slot at the bottom is too small for the connector on my third-party docking cables.
• The rubber is a little too grippy; it snags against my pocket when I'm pulling the phone out.

I don't mind the first drawback, because I don't use a dock. I don't mind the second, because I have plenty of Apple cables. The pocket-snagging, though — that was a minor annoyance but one that was repeated many times a day.

My solution was to remove the bumper and instead apply four translucent rubber dots to the back of the phone. As you can see from the packaging, these flat dots are also called "bumpers." They are originally to keep lamps and vases from sliding and scratching furniture.

Benefits of the dots:

• I'm back to the original sleek feel of the phone, which I like.
• I get the gripping benefits I got with Apple's bumper.
• The pocket-snagging is no longer an issue.
• There is airflow under the phone, sort of like what Bluelounge's Cool Feet do for laptops (the effect is probably negligible, but the phone does get pretty warm sometimes).
• The dots cost practically nothing.

I could probably run a scam on eBay advertising brand-new iPhone "bumpers" for five dollars apiece.

Drawbacks:

• The back of the phone is now ugly — but when I'm using it I only look at the front anyway.
• I'm no longer comfortable laying the phone face-down — but that's a tradeoff I can live with.
• Pocket lint will gather around the edges of the dots — but I can live with that too.

I forget exactly when I did this, but after a few days the dots have stayed stuck on pretty well. No signs of peeling. I got mine from Bed Bath and Beyond, in a package that included more dots and more kinds of dots than I needed. They might also be available at hardware stores or office supply stores.