No hacks are currently available and thus you cannot install them.
According to Wololo.net, you can safetly update to 2.02. Follow that site - from time to time, hackers release titles of PSP games you can download from PSN that are exploitable. It's literally a time attack, but if you manage to get a copy before the game's pulled off PSN, you can swap its save file and use it to launch eCFW, which gives you full access to the PSP sandbox, meaning, you can launch PSP ISO's and homebrew. Other than that, there are no exploits for the system. There is a promise of UVLoader - a User-Mode loader for PSVita Mode, but it's still a Work-in-Progress and nobody knows when it will be officially released.
In any case, that about covers it.