There are several useful [txpool queries](https://github.com/ethereum/go-ethereum/wiki/Management-APIs#txpool) in geth: `txpool_content`, `txpool_inspect` and `txpool_status`. Since these are not part of the general standard, Parity likely has some other name for the same mechanism.

Ideally, I would get a list of transaction details or hashes that are pending for a supplied account. Although, geth doesn't have an option to filter the results by account, as far as I can tell.