I recently purchased and started using a wireless keyboard with my iPad. Since I write, it's proved to be a great tool for me in terms of getting work done by tablet. I'm still on the 2007 MacBook and it definitely does not fit in a regular sized purse. A couple of friends received styluses during the holidays, which sparked discussions of whether they'd really be useful (or not) with a phone or tablet.
After our conversation we came to agreement the best uses for a stylus were:
If You Write in a Foreign Language: Some of our friends who text or email in language other than English find a stylus essential. Especially when it comes to writing characters, you can write faster and more legibly with a stylus. One of our friends had a keychain on her phone with a small stylus conveniently attached for writing messages in Japanese.
If Your Smartphone Has a Huge Screen: If you're an owner of one of the Samsung Galaxy Note/Note II models, a stylus seems to come in handy because the phone's screen is in that sweet spot between a standard smartphone and a tablet. Especially for gaming, sometimes it's a bit easier to use a stylus than your finger for games like Draw Something or even match 3 games.
If You Live in a Cold Climate Area: Unless you want to buy a pair of touchscreen friendly gloves, another solution for accessing your phone or tablet in the cold is with a stylus.
If You Like to Draw: As I mentioned before, for games like Draw Something, you can achieve a lot more accuracy with a stylus. If you're an artist and like to use your smartphone or table to doodle, it definitely lets you get more detailed versus using your finger.
Share what other situations a stylus comes in handy for you, and whether you find use for one on your smartphone or tablet.