Why are my updating iPhone apps "waiting..." forever? I've got an iPhone 4, not quite sure which version of iOS, but I keep current.

Recently, I got an update for one of the apps, started it, and then for some reason it got stuck on "Waiting..." indefinitely.  Another app later offered an upgrade, and when I accepted it got stuck on "Waiting...".  This has been a few days now, with both 3G and wireless available, with no change.

The apps don't have the "delete" button when I touch and hold on them, and I tried deleting them in iTunes but after syncing my iPhone there was no visible change.  (They're free apps, so deleting and reloading is a fine solution, but knowing how to kick-start the updater would be nice.)  The App Store app simply tells me they've been updated.

Any suggestions?
I get that problem sometimes too on my iPhone 4, especially if I'm updating an app and I lose network coverage. 

Here's what I'll usually do, either:


Sync with iTunes
Restart my phone by holding down the power and home buttons. 


Either of those fixes the problem for me.