Just got Soul Silver and couldnt wait to get to the daycare so I can bring my two caught pairs of magikarp and pineco's and have them bang each other ferociously while gaining levels.
So far I have a level 1 adamant nature pineco named Spike (*was thinking of cowboy beebop, oddly*), and my magikarps are breeding like... magikarps. Trying to get me an adamant karp. When I get said karp, I plan to name it Naga.
Then when I find an area with teddiursa... yeah.
In case you were wondering, pokemon trained from level 1 are always stronger than same leveled pokemon caught in the wild, and natures effect stat bonuses as well. So a bred pokemon with the right nature will be quite more powerful than a caught pokemon of same level.
And for those wondering, my current lineup is Quilava 19 (Zuko), Ledian 20 (Lady), and Pineco 1 (Spike). Lady I caught at level three, and she has a Modest nature. My future lineup includes Magikarp, Teddiursa, and Skarmory. Which I all intend to breed.