There is something I hate about Nintendo when it comes to encourage people to go outside or expand their game beyond the console itself, they always put stupid caps on their stuff.
Pokewalker
>you can go outside and walk to give your pokemon some extra EXP.
>you can also capture some uncommon pokemon and get items.
>BUT your pokemon can only gain 1 level at most.
>it will NOT learn moves this way unlike daycare.
Play Coins
>you can earn them by walking around.
>you can use them in certain games as currency.
>BUT you cannot earn more than 10 per day.
>also, you cannot hold more than 300 in total.
>very few games use them despite being a good alternative to grinding and farming.
Pokemon Dream World (dead)
>you could collect berries and other items.
>you could befriend and get uncommon pokemon.
>BUT you could only play it 1 hour per day.
>you could also not send more than 1 befriended pokemon to your game per session.
>Black and White got the short end of the stick when it came to getting berries after they closed the DW.