You can buy btc with linden at the virwox exchange
Yep, there rates are very bad, and on top of that it still takes up to 48 hours to send the BTC, AND it can only be linden you buy from their site

Since linden lab changed their rules you can no longer put your L$ into their terminals. Sucks though seems I was a bit late for all that.
Just used it a few minutes ago to try it out, and yes, the rates are very bad. Payed 20 through PayPal, bought SLL, bought BTC and in the end I had 15.4 worth of BTC (according to
https://bitcoinaverage.com/#EUR).
Yep, terrible rates at virwox when it comes to BTC. If worse comes to worse though I'll end up using them, even though I will have to wait up to 48 hours. ((Until coinbase finally verifies my bank account.)) Would much rather trade to a person with better rates, and faster speed. If anyone is interested just let me know and we can come to a deal. I'm definitely more than willing to give a more than fair rate!
However, if you already have SLL, you don't have to pay Paypal's fee and the rate for USD to SLL. So maybe it isn't that bad in your case.
Well, I don't have SLL on virwox, so I would still need to deal with their paypal rates and wait time. Before Linden Lab changed their TOS, SL residents were able to deposit linden to terminals for virwox, but not anymore.

Accepting Second Life L$ is extremly risky,
even more risky then accepting PayPal.
Think twice if you really, really trust the person you're dealing with, or you will most likely lose money.
As stated I am willing to go first, and for my safety I would just go in increments.
From another post:
http://gyazo.com/539151dc05f4410c4c77cd58607c52b7I trade SL currency for USD pretty often.
The ratio I came to is this:
L$2,000 ((Equal to $7 - 7.50 USD)) Vs 0.01 BTC ((Currently $6.20))