TMs. I've been through Yellow, Silver and most of Crystal, and I've used maybe 3 TMs. A TM (Technical Machine) is a unique item that teaches a new attack move to one of your pokemon. But once you use it, it's gone. This is probably why I generally don't use them, because I feel like I must keep every item I find. My packrat mentality even keeps me from selling off Nuggets for money.
As I recall, each game has had a couple TMs that you absolutely must utilize if you want to progress. Grudgingly, I've used them. In Sapphire, one of these is Secret Power, which is the move you have to use if you want to establish a Secret Base. Secret Power allows you to carve a base out of the side of a mountain or create a treehouse in certain trees. You can decorate your base with pokemon dolls and furniture. The interesting thing is that you can send a copy of your Secret Base into other player's games, creating the illusion that you and your friends are all in the same game.
I was out talking to my third grade neighbor Matt last night, and he was excitedly letting me know how his Sapphire game was going. He got the game a couple days after I did, but he has already passed me, and started and re-started several times. During one of his games, he only trained up his Torchic, ignoring the rest of his team, which I thought was an interesting way to toy with the game. When I see him next, hopefully we can do some battling or Secret Base trading.
My Taillow evolved into a Swellow. He's obviously being groomed for the Fly move, so I can Fly from town to town instead of all this tedious walking. I should probably come up with a cool nickname for him. Something sharp, something fast. I'll get back to you.
But quickly becoming my favorite party member is my Sableye, another beast in need of a nickname. I've maxxed out her PokeBlock intake for the pageants, and her Night Shade attack has become a battling staple. It also helps that she looks like the low-level Heartless nasties from Kingdom Hearts. I think Sableye and I are going to go all the way to the Championships together.
Time: 12:42
Badges: 3
Pokedex: 33
Party: Swellow lv25, Gringo (Mightyena) lv23, Sableye lv26, Grovyle lv25, Plusle lv16, Minun lv17