All I've been doing in Diamond lately was training... I want to get all my migrated Pokemon to level 45 before getting my eighth badge, and my E4 team to level 50.
(In this game, I have sixty or so Pokemon I'm raising to the same level... you can imagine how much time that's taking. I do have one team that will eventually take on the E4 though... you can probably consider that my main battling team.)
I recently got my fire Pokemon to level 45, which included a Flareon, Magmar, and Charizard. Later on I got my Jolteon, Tangrowth, Venusaur, and Leafeon to level 45, after training in Route 222 and 223. So now most of my Eeveelutions are at level 45; the exception is Umbreon, who's still at level 41 and a pain to train. The only other underleveled Pokemon I have are Persian (40), Hypno (42), Venomoth (40), Yanmega (40), and Seviper (37).
What I might do, though, is put one or two of those Pokemon in daycare (maybe Yanmega and Venomoth so they can make Yanma eggs), and just go for badge 8 without finishing this training. Then I'll train only my E4 team for the E4, maybe to level 60. I gotta find something to do with the max money I have, after all...
Today I went underground for a while, and dug up a LOT of stuff. I found:
6 Thunderstones
2 Everstones
4 Fire Stones
6 Heart Scales
4 Hard Stones
2 Helix Fossils
Skull Fossil
Damp Rock
3 Heat Rocks
3 Revives
Water Stone
Leaf Stone
Yellow Shard
Icy Rock
Star Piece
Light Clay
Rare Bone
Blue Shard
As you probably guessed, I have the National Dex already. This proves that you don't need to beat the E4 to get it... Also, the News Centre in Solaceon asked me for a Steelix today. I had one sitting in my box, so I showed it... and got three ordinary Pokeballs. What a ripoff, especially for a Pokemon that's hard to catch.
My progress so far:
Badges: 7
Play Time: 602:40
Pokedex: 217 seen, 212 caught
Money: 999999
Team:
Dreamboat (Milotic, level 45)
Morticia (Spiritomb, level 47)
William (Roserade, level 50)
Zorro (Lucario, level 50)
Saphira (Garchomp, level 50)
Shin (Ninetales, level 45)