A common problem of indie podcasts is excessive or unwanted background noise and room sounds. Several companies have responded by marketing mini vocal booths that are portable and help block out unwanted sounds.

Instructables has published a tutorial on building a DIY portable mini vocal booth:

The DIY Portable Mini Vocal Booth is ideal for podcasters, DIY filmakers and sound designers alike. My personal motivation to build this, was a desire to have a mobile mini deadroom to make foley recordings and recordings for my music.

It’s probably not going to do the job as well as a professionally designed portable sound booth, but it’s cheap to build and could be a useful tool for improving the sound of your recordings.