I have a decent idea in mind. I don't see a lot of stuff around for what I have in mind and stuff that is around is implemented badly. Kind of like expert-exchange vs. stackoverflow.
I have not worked on a project by myself before, I've just been involved in working with teams for last couple of years. So I am scared to tackle what I have in mind by myself and doubting skills I already know. Language/framework I consider myself proficient in is Java/Struts2 However, I've been wanting to learn RoR or Grails. So I need advice whether on I should implement initial version of the idea with tools I already know (Don't worry, be crapy) or start with learning new tool and side by side implement the idea?
It depends:
If so, learn a new language, If you have the time then it would be just great!!
but if
Then make it in the technology you command right now. But make sure it does what you need and that technology may be up to the challenge.
Using the right tool for the job is the best, always, but I you need to cut a table TODAY an you only have a Hammer, start punching already!!!